diff --git a/cloud b/cloud
index ba1a4f2b..b4231e14 100755
--- a/cloud
+++ b/cloud
@@ -112,6 +112,7 @@ function execute_command() {
     declare -r load_queue_trigger_topic="${prefix}load_queue_trigger"
     declare -r cache_bucket_name="${project}_${prefix}cache"
     declare -r pick_notifications_trigger_topic="${prefix}pick_notifications_trigger"
+    declare -r purge_op_db_trigger_topic="${prefix}purge_op_db_trigger"
     declare -r cache_redirect_function_name="cache_redirect"
     declare cache_redirector_url="https://${CLOUD_FUNCTION_REGION}"
     declare cache_redirector_url+="-${project}.cloudfunctions.net/"
@@ -255,6 +256,7 @@ function execute_command() {
         --new-load-subscription="$new_load_subscription"
         --updated-publish="$updated_publish"
         --updated-topic="$updated_topic"
+        --purge-op-db-trigger-topic="$purge_op_db_trigger_topic"
         --updated-urls-topic="$updated_urls_topic"
         --spool-collection-path="$spool_collection_path"
         --extra-cc="$extra_cc"
@@ -310,6 +312,7 @@ function execute_command() {
             --updated-debug-subscription="$updated_debug_subscription" \
             --pick-notifications-trigger-topic \
               "$pick_notifications_trigger_topic" \
+            --purge-op-db-trigger-topic "$purge_op_db_trigger_topic" \
             --smtp-topic="$smtp_topic" \
             --smtp-subscription="$smtp_subscription"
         sections_run "$sections" firestore_deploy "$project"
@@ -322,6 +325,7 @@ function execute_command() {
             --load-queue-trigger-topic="$load_queue_trigger_topic" \
             --pick-notifications-trigger-topic \
               "$pick_notifications_trigger_topic" \
+            --purge-op-db-trigger-topic "$purge_op_db_trigger_topic" \
             --updated-urls-topic="$updated_urls_topic" \
             --updated-topic="$updated_topic" \
             --cache-redirect-function-name="$cache_redirect_function_name" \
@@ -331,7 +335,8 @@ function execute_command() {
             --project="$project" \
             --prefix="$prefix" \
             --load-queue-trigger-topic="$load_queue_trigger_topic" \
-            --pick-notifications-trigger-topic="$pick_notifications_trigger_topic"
+            --pick-notifications-trigger-topic="$pick_notifications_trigger_topic" \
+            --purge-op-db-trigger-topic="$purge_op_db_trigger_topic"
         sections_run "$sections" submitters_deploy \
             "$project" "$new_topic" "${submitters[@]}"
     elif [ "$command" == "shell" ]; then
@@ -361,6 +366,7 @@ function execute_command() {
             --load-queue-trigger-topic="$load_queue_trigger_topic" \
             --pick-notifications-trigger-topic \
               "$pick_notifications_trigger_topic" \
+            --purge-op-db-trigger-topic "$purge_op_db_trigger_topic" \
             --new-topic="$new_topic" \
             --new-load-subscription="$new_load_subscription" \
             --new-debug-subscription="$new_debug_subscription" \
diff --git a/kcidb/cloud/cloud_functions.sh b/kcidb/cloud/cloud_functions.sh
index a2dfe3dc..397a21ba 100644
--- a/kcidb/cloud/cloud_functions.sh
+++ b/kcidb/cloud/cloud_functions.sh
@@ -16,6 +16,7 @@ declare _CLOUD_FUNCTIONS_SH=
 #       --new-topic=NAME --new-load-subscription=NAME
 #       --updated-publish=true|false
 #       --updated-topic=NAME
+#       --purge-op-db-trigger-topic=NAME
 #       --updated-urls-topic=NAME
 #       --cache-bucket-name=NAME
 #       --cache-redirector-url=URL
@@ -38,6 +39,7 @@ function cloud_functions_env() {
                           heavy_asserts \
                           new_topic new_load_subscription \
                           updated_publish updated_topic \
+                          purge_op_db_trigger_topic \
                           updated_urls_topic \
                           spool_collection_path \
                           extra_cc \
@@ -70,6 +72,7 @@ function cloud_functions_env() {
         [KCIDB_CLEAN_TEST_DATABASES]="$clean_test_databases"
         [KCIDB_EMPTY_TEST_DATABASES]="$empty_test_databases"
         [KCIDB_UPDATED_QUEUE_TOPIC]="$updated_topic"
+        [KCIDB_PURGE_OP_DB_TRIGGER_TOPIC]="$purge_op_db_trigger_topic"
         [KCIDB_UPDATED_URLS_TOPIC]="$updated_urls_topic"
         [KCIDB_SELECTED_SUBSCRIPTIONS]=""
         [KCIDB_SPOOL_COLLECTION_PATH]="$spool_collection_path"
@@ -123,6 +126,7 @@ function cloud_functions_env() {
 #       --project=NAME --prefix=PREFIX --source=PATH
 #       --load-queue-trigger-topic=NAME
 #       --pick-notifications-trigger-topic=NAME
+#       --purge-op-db-trigger-topic=NAME
 #       --updated-urls-topic=NAME
 #       --updated-topic=NAME
 #       --spool-collection-path=PATH
@@ -133,6 +137,7 @@ function cloud_functions_deploy() {
     params="$(getopt_vars sections project prefix source \
                           load_queue_trigger_topic \
                           pick_notifications_trigger_topic \
+                          purge_op_db_trigger_topic \
                           updated_urls_topic \
                           updated_topic \
                           spool_collection_path \
@@ -152,6 +157,14 @@ function cloud_functions_deploy() {
     trigger_event+="document.create"
     declare trigger_resource="projects/$project/databases/(default)/documents/"
     trigger_resource+="${spool_collection_path}/{notification_id}"
+    cloud_function_deploy "$sections" "$source" "$project" "$prefix" \
+                          purge_op_db \
+                          --env-vars-file "$env_yaml_file" \
+                          --trigger-topic "${purge_op_db_trigger_topic}" \
+                          --memory 256MB \
+                          --max-instances=1 \
+                          --timeout 540
+
     cloud_function_deploy "$sections" "$source" "$project" "$prefix" \
                           pick_notifications \
                           --env-vars-file "$env_yaml_file" \
@@ -215,6 +228,8 @@ function cloud_functions_withdraw() {
                           cache_redirect_function_name \
                           -- "$@")"
     eval "$params"
+    cloud_function_withdraw "$sections" "$project" "$prefix" \
+                            purge_op_db
     cloud_function_withdraw "$sections" "$project" "$prefix" \
                             pick_notifications
     cloud_function_withdraw "$sections" "$project" "$prefix" \
diff --git a/kcidb/cloud/pubsub.sh b/kcidb/cloud/pubsub.sh
index 3560c635..5cfda7f4 100644
--- a/kcidb/cloud/pubsub.sh
+++ b/kcidb/cloud/pubsub.sh
@@ -134,6 +134,7 @@ function pubsub_subscription_withdraw() {
 #       --updated-topic=NAME
 #       --updated-debug-subscription=NAME
 #       --pick-notifications-trigger-topic=NAME
+#       --purge-op-db-trigger-topic=NAME
 #       --updated-urls-topic=NAME
 #       --smtp-topic=NAME
 #       --smtp-subscription=NAME
@@ -147,6 +148,7 @@ function pubsub_deploy() {
                           updated_topic \
                           updated_debug_subscription \
                           pick_notifications_trigger_topic \
+                          purge_op_db_trigger_topic \
                           updated_urls_topic \
                           smtp_topic smtp_subscription \
                           -- "$@")"
@@ -167,6 +169,7 @@ function pubsub_deploy() {
     pubsub_subscription_deploy "$project" "${updated_topic}" \
                                "${updated_debug_subscription}"
     pubsub_topic_deploy "$project" "${pick_notifications_trigger_topic}"
+    pubsub_topic_deploy "$project" "${purge_op_db_trigger_topic}"
     pubsub_topic_deploy "$project" "${updated_urls_topic}"
     if [ -n "$smtp_topic" ]; then
         pubsub_topic_deploy "$project" "$smtp_topic"
@@ -179,6 +182,7 @@ function pubsub_deploy() {
 # Args: --project=NAME
 #       --load-queue-trigger-topic=NAME
 #       --pick-notifications-trigger-topic=NAME
+#       --purge-op-db-trigger-topic=NAME
 #       --updated-urls-topic=NAME
 #       --new-topic=NAME
 #       --new-load-subscription=NAME
@@ -192,6 +196,7 @@ function pubsub_withdraw() {
     params="$(getopt_vars project \
                           load_queue_trigger_topic \
                           pick_notifications_trigger_topic \
+                          purge_op_db_trigger_topic \
                           updated_urls_topic \
                           new_topic \
                           new_load_subscription \
@@ -213,6 +218,7 @@ function pubsub_withdraw() {
     pubsub_topic_withdraw "$project" "$load_queue_trigger_topic"
     pubsub_topic_withdraw "$project" "$pick_notifications_trigger_topic"
     pubsub_topic_withdraw "$project" "$updated_urls_topic"
+    pubsub_topic_withdraw "$project" "$purge_op_db_trigger_topic"
 }
 
 fi # _PUBSUB_SH
diff --git a/kcidb/cloud/scheduler.sh b/kcidb/cloud/scheduler.sh
index 01b33629..40e217a7 100644
--- a/kcidb/cloud/scheduler.sh
+++ b/kcidb/cloud/scheduler.sh
@@ -66,12 +66,14 @@ function scheduler_job_withdraw() {
 #       --prefix=STRING
 #       --load-queue-trigger-topic=NAME
 #       --pick-notifications-trigger-topic=NAME
+#       --purge-op-db-trigger-topic=NAME
 function scheduler_deploy() {
     declare params
     params="$(getopt_vars project \
                           prefix \
                           load_queue_trigger_topic \
                           pick_notifications_trigger_topic \
+                          purge_op_db_trigger_topic \
                           -- "$@")"
     eval "$params"
     # Deploy the jobs
@@ -80,6 +82,9 @@ function scheduler_deploy() {
     scheduler_job_pubsub_deploy "$project" "${prefix}pick_notifications_trigger" \
                                 "$pick_notifications_trigger_topic" \
                                  '*/10 * * * *' '{}'
+    scheduler_job_pubsub_deploy "$project" "${prefix}purge_op_db_trigger" \
+                                "$purge_op_db_trigger_topic" \
+                                 '0 6 * * MON' '{"delta": {"months": 6}}'
 }
 
 # Withdraw from the scheduler
@@ -89,6 +94,7 @@ function scheduler_withdraw() {
     declare -r prefix="$1"; shift
     scheduler_job_withdraw "$project" "${prefix}load_queue_trigger"
     scheduler_job_withdraw "$project" "${prefix}pick_notifications_trigger"
+    scheduler_job_withdraw "$project" "${prefix}purge_op_db_trigger"
 }
 
 fi # _SCHEDULER_SH
diff --git a/kcidb/cloud/sections.sh b/kcidb/cloud/sections.sh
index 39f0d951..a6e4f160 100644
--- a/kcidb/cloud/sections.sh
+++ b/kcidb/cloud/sections.sh
@@ -14,6 +14,7 @@ declare -A -r SECTIONS=(
     ["secrets"]="Secrets"
     ["firestore"]="Firestore database"
     ["storage"]="Google cloud storage"
+    ["cloud_functions.purge_op_db"]="Cloud Functions: kcidb_purge_op_db()"
     ["cloud_functions.pick_notifications"]="Cloud Functions: kcidb_pick_notifications()"
     ["cloud_functions.send_notification"]="Cloud Functions: kcidb_send_notification()"
     ["cloud_functions.spool_notifications"]="Cloud Functions: kcidb_spool_notifications()"
diff --git a/kcidb/misc.py b/kcidb/misc.py
index 25ee5c34..204f571f 100644
--- a/kcidb/misc.py
+++ b/kcidb/misc.py
@@ -9,10 +9,14 @@
 import argparse
 import logging
 import json
+import datetime
 from textwrap import indent
 from importlib import metadata
+import dateutil
+import dateutil.relativedelta
 import dateutil.parser
 from google.cloud import secretmanager
+import jsonschema
 import jq
 import kcidb.io as io
 
@@ -482,3 +486,72 @@ def isliced(iterable, size):
         if not iterator_slice:
             break
         yield iterator_slice
+
+
+def parse_timedelta_json(data, stamp):
+    """
+    Parse JSON data for a time delta: an optional timestamp, and an optional
+    delta, but at least one of them must be present. If the timestamp is not
+    present the "stamp" is used instead. The delta can only be positive and is
+    subtracted from the timestamp. The timestamp is rounded down to the
+    precision of the delta, based on the presence of its components in the
+    JSON.
+
+    Args:
+        data:   The JSON data to parse.
+        stamp:  The (aware) timestamp to use, if not present in the data.
+    """
+    # Recognized time components, smaller to larger, and their minimums
+    components_min = dict(
+        microseconds=0,
+        seconds=0,
+        minutes=0,
+        hours=0,
+        days=1,
+        months=1,
+        years=1,
+    )
+    # The timedelta schema
+    schema = dict(
+        type="object",
+        properties=dict(
+            delta=dict(
+                type="object",
+                properties={
+                    # Delta is always positive and is subtracted to reduce
+                    # chance of forgetting the sign and going to the future,
+                    # wiping everything
+                    c: dict(type="integer", minimum=0)
+                    for c in components_min
+                },
+                anyOf=[dict(required=[c]) for c in components_min],
+                additionalProperties=False,
+            ),
+            stamp=dict(type="string", format="date-time",),
+        ),
+        anyOf=[{"required": ["delta"]}, {"required": ["stamp"]},],
+        additionalProperties=False,
+    )
+
+    assert isinstance(stamp, datetime.datetime) and stamp.tzinfo
+    jsonschema.validate(
+        instance=data, schema=schema,
+        format_checker=jsonschema.Draft7Validator.FORMAT_CHECKER
+    )
+
+    # Use the base timestamp from the data, if present
+    if "stamp" in data:
+        stamp = dateutil.parser.isoparse(data["stamp"])
+
+    # Retrieve and apply the timedelta from input, if any
+    if "delta" in data:
+        delta = data["delta"].copy()
+        # Round the timestamp down to delta precision and subtract delta
+        for component, minimum in components_min.items():
+            if component in delta:
+                break
+            # Singular means replace with value
+            delta[component[:-1]] = minimum
+        stamp = stamp - dateutil.relativedelta.relativedelta(**delta)
+
+    return stamp
diff --git a/kcidb/test_misc.py b/kcidb/test_misc.py
new file mode 100644
index 00000000..e6d172dd
--- /dev/null
+++ b/kcidb/test_misc.py
@@ -0,0 +1,88 @@
+"""kcdib.misc module tests"""
+
+import datetime
+from pytest import raises
+from jsonschema.exceptions import ValidationError
+import kcidb.misc
+
+
+def test_parse_timedelta_json():
+    """Check kcidb-tests-validate works"""
+    f = kcidb.misc.parse_timedelta_json
+    min_stamp = datetime.datetime(1, 1, 1, 0, 0, 0, 0,
+                                  tzinfo=datetime.timezone.utc)
+    stamp = datetime.datetime(1, 2, 3, 4, 5, 6, 7,
+                              tzinfo=datetime.timezone.utc)
+    stamp_str = stamp.isoformat(timespec="microseconds")
+    with raises(ValidationError):
+        f([], stamp)
+    with raises(ValidationError):
+        f({}, stamp)
+    with raises(ValidationError):
+        f(dict(stamp=10), stamp)
+    with raises(ValidationError):
+        f(dict(stamp=""), stamp)
+    with raises(ValidationError):
+        f(dict(delta=10), stamp)
+    with raises(ValidationError):
+        f(dict(delta=""), stamp)
+    with raises(ValidationError):
+        f(dict(delta={}), stamp)
+    with raises(ValidationError):
+        f(dict(delta=dict(seconds=-1)), stamp)
+
+    assert f(dict(stamp=stamp_str), min_stamp) == stamp
+    assert f(dict(delta=dict(microseconds=0), stamp=stamp_str),
+             min_stamp) == stamp
+
+    assert f(dict(delta=dict(microseconds=0)), stamp) == stamp
+    assert f(dict(delta=dict(seconds=0, microseconds=0)), stamp) == stamp
+    assert f(dict(delta=dict(minutes=0, seconds=0, microseconds=0)),
+             stamp) == stamp
+    assert f(dict(delta=dict(hours=0, minutes=0, seconds=0, microseconds=0)),
+             stamp) == stamp
+    assert f(dict(delta=dict(days=0,
+                             hours=0, minutes=0, seconds=0, microseconds=0)),
+             stamp) == stamp
+    assert f(dict(delta=dict(months=0, days=0,
+                             hours=0, minutes=0, seconds=0, microseconds=0)),
+             stamp) == stamp
+    assert f(dict(delta=dict(years=0, months=0, days=0,
+                             hours=0, minutes=0, seconds=0, microseconds=0)),
+             stamp) == stamp
+    assert f(dict(delta=dict(seconds=0)), stamp) == \
+        datetime.datetime(1, 2, 3, 4, 5, 6, tzinfo=datetime.timezone.utc)
+    assert f(dict(delta=dict(minutes=0)), stamp) == \
+        datetime.datetime(1, 2, 3, 4, 5, tzinfo=datetime.timezone.utc)
+    assert f(dict(delta=dict(hours=0)), stamp) == \
+        datetime.datetime(1, 2, 3, 4, tzinfo=datetime.timezone.utc)
+    assert f(dict(delta=dict(days=0)), stamp) == \
+        datetime.datetime(1, 2, 3, tzinfo=datetime.timezone.utc)
+    assert f(dict(delta=dict(months=0)), stamp) == \
+        datetime.datetime(1, 2, 1, tzinfo=datetime.timezone.utc)
+    assert f(dict(delta=dict(years=0)), stamp) == min_stamp
+
+    assert f(
+        dict(delta=dict(years=0), stamp=stamp_str),
+        min_stamp
+    ) == min_stamp
+    assert f(
+        dict(delta=dict(years=0, months=1, days=2), stamp=stamp_str),
+        min_stamp
+    ) == min_stamp
+
+    assert f(
+        dict(delta=dict(months=6)),
+        datetime.datetime(2023, 12, 15, 15, 52, 24, 204547,
+                          tzinfo=datetime.timezone.utc)
+    ) == datetime.datetime(2023, 6, 1, tzinfo=datetime.timezone.utc)
+
+    assert f(
+        dict(delta=dict(months=2)),
+        datetime.datetime(2023, 3, 31, 21, 11, 1, tzinfo=datetime.timezone.utc)
+    ) == datetime.datetime(2023, 1, 1, tzinfo=datetime.timezone.utc)
+
+    assert f(
+        dict(delta=dict(months=3)),
+        datetime.datetime(2023, 4, 3, 2, 1, tzinfo=datetime.timezone.utc)
+    ) == datetime.datetime(2023, 1, 1, tzinfo=datetime.timezone.utc)
diff --git a/main.py b/main.py
index 6ce83f73..fb7c667f 100644
--- a/main.py
+++ b/main.py
@@ -4,6 +4,7 @@
 import atexit
 import tempfile
 import base64
+import json
 import datetime
 import logging
 import smtplib
@@ -421,6 +422,27 @@ def kcidb_pick_notifications(data, context):
         spool_client.ack(notification_id)
 
 
+def kcidb_purge_op_db(event, context):
+    """
+    Purge data from the operational database, older than the optional delta
+    from the current (or specified) database timestamp, rounded to smallest
+    delta component. Require that either the delta or the timestamp are
+    present.
+    """
+    # Parse the input JSON
+    string = base64.b64decode(event["data"]).decode()
+    data = json.loads(string)
+
+    # Get the operational database client
+    client = get_db_client(OPERATIONAL_DATABASE)
+
+    # Parse/calculate the cut-off timestamp
+    stamp = kcidb.misc.parse_timedelta_json(data, client.get_current_time())
+
+    # Purge the data
+    client.purge(stamp)
+
+
 def send_message(message):
     """
     Send message via email.
diff --git a/test_main.py b/test_main.py
index d005b055..9371c5df 100644
--- a/test_main.py
+++ b/test_main.py
@@ -3,6 +3,8 @@
 import os
 import subprocess
 import unittest
+from copy import deepcopy
+from datetime import datetime, timezone, timedelta
 from importlib import import_module
 from urllib.parse import quote
 import time
@@ -222,3 +224,124 @@ def test_url_caching(empty_deployment):
         if check_url_in_cache(url_not_expected):
             raise AssertionError(f"Unexpected URL '{url_not_expected}' \
                 found in the cache")
+
+
+def test_purge_op_db(empty_deployment):
+    """Check kcidb_purge_op_db() works correctly"""
+
+    # Make empty_deployment appear used to silence pylint warning
+    assert empty_deployment is None
+
+    # Use the current time to avoid deployment purge trigger
+    timestamp_before = datetime.now(timezone.utc)
+    str_before = timestamp_before.isoformat(timespec="microseconds")
+
+    data_before = dict(
+        version=dict(
+            major=kcidb.io.SCHEMA.major, minor=kcidb.io.SCHEMA.minor
+        ),
+        checkouts=[dict(
+            id="origin:1", origin="origin",
+            _timestamp=str_before
+        )],
+        builds=[dict(
+            id="origin:1", origin="origin", checkout_id="origin:1",
+            _timestamp=str_before
+        )],
+        tests=[dict(
+            id="origin:1", origin="origin", build_id="origin:1",
+            _timestamp=str_before
+        )],
+        issues=[dict(
+            id="origin:1", origin="origin", version=1,
+            _timestamp=str_before
+        )],
+        incidents=[dict(
+            id="origin:1", origin="origin",
+            issue_id="origin:1", issue_version=1,
+            _timestamp=str_before
+        )],
+    )
+
+    timestamp_after = timestamp_before + timedelta(microseconds=1)
+    str_after = timestamp_after.isoformat(timespec="microseconds")
+
+    data_after = dict(
+        version=dict(
+            major=kcidb.io.SCHEMA.major, minor=kcidb.io.SCHEMA.minor
+        ),
+        checkouts=[dict(
+            id="origin:2", origin="origin",
+            _timestamp=str_after
+        )],
+        builds=[dict(
+            id="origin:2", origin="origin", checkout_id="origin:2",
+            _timestamp=str_after
+        )],
+        tests=[dict(
+            id="origin:2", origin="origin", build_id="origin:2",
+            _timestamp=str_after
+        )],
+        issues=[dict(
+            id="origin:2", origin="origin", version=1,
+            _timestamp=str_after
+        )],
+        incidents=[dict(
+            id="origin:2", origin="origin",
+            issue_id="origin:2", issue_version=1,
+            _timestamp=str_after
+        )],
+    )
+
+    def filter_test_data(data):
+        """Filter objects created by this test from I/O data"""
+        return {
+            key: [
+                deepcopy(obj) for obj in value
+                if obj.get("_timestamp") in (str_before, str_after)
+            ] if key and key in kcidb.io.SCHEMA.graph
+            else deepcopy(value)
+            for key, value in data.items()
+        }
+
+    # Merge the before and after data
+    data = kcidb.io.SCHEMA.merge(data_before, [data_after])
+
+    # Load the merged data into the database
+    client = kcidb.db.Client(os.environ["KCIDB_DATABASE"])
+    client.load(data, with_metadata=True)
+    dump = filter_test_data(client.dump())
+    for obj_list_name in kcidb.io.SCHEMA.graph:
+        if obj_list_name:
+            assert len(dump.get(obj_list_name, [])) == 2, \
+                f"Invalid number of {obj_list_name}"
+
+    # Trigger the purge at the boundary
+    kcidb.mq.JSONPublisher(
+        os.environ["GCP_PROJECT"],
+        os.environ["KCIDB_PURGE_OP_DB_TRIGGER_TOPIC"]
+    ).publish(dict(stamp=str_after))
+
+    # Wait and check for the purge
+    deadline = datetime.now(timezone.utc) + timedelta(minutes=5)
+    while datetime.now(timezone.utc) < deadline:
+        dump = filter_test_data(client.dump())
+        # If data has changed
+        if not all(
+            len(dump.get(n, [])) == 2
+            for n in kcidb.io.SCHEMA.graph
+            if n
+        ):
+            assert dump == data_after
+            break
+        time.sleep(5)
+    else:
+        assert False, "Operational database purge timed out"
+
+    # Make sure we were getting the operational DB dump
+    op_client = kcidb.db.Client(os.environ["KCIDB_OPERATIONAL_DATABASE"])
+    assert dump == filter_test_data(op_client.dump())
+
+    # Make sure the archive database is still intact
+    ar_client = kcidb.db.Client(os.environ["KCIDB_ARCHIVE_DATABASE"])
+    assert filter_test_data(ar_client.dump()) == data