# Topic published on 'Invalid date' with ActivityPub

**URL:** https://meta.discourse.org/t/topic-published-on-invalid-date-with-activitypub/360228
**Category:** Bug
**Tags:** activitypub
**Created:** [April 3, 2025, 1:16pm UTC](https://meta.discourse.org/t/topic-published-on-invalid-date-with-activitypub/360228 "2025-04-03T13:16:47Z")
**Posts on this page:** 1
**Showing post:** 5

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### Author: ![pmusaraj](https://sea3.discourse-cdn.com/meta/user_avatar/meta.discourse.org/pmusaraj/32/119489_2.png) [@pmusaraj](https://meta.discourse.org/u/pmusaraj)
#### Post date: [August 28, 2025, 2:23pm UTC](https://meta.discourse.org/t/topic-published-on-invalid-date-with-activitypub/360228/5 "2025-08-28T14:23:21Z")

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Oh, I added a partial fix for this in [DEV: Ensure activity\_pub\_published\_at returns a single date by pmusaraj · Pull Request #243 · discourse/discourse-activity-pub · GitHub](https://github.com/discourse/discourse-activity-pub/pull/243), I think. If you rebuild your instance @adulau you should no longer see this issue.

The underlying bug isn’t fixed. In some cases, the plugin creates multiple `activity_pub_published_at` custom fields for the same object, which results in the serializer returning an array of dates for `topic.activity_pub_published_at`. Often these are the same date added twice in the array. The frontend code (Moment) doesn’t know how to interpret an array of dates and outputs `invalid date`. The fix above ensures the serializer always outputs a single date (without yet fixing the underlying reason for multiple custom fields).

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_[View the full topic](https://meta.discourse.org/t/topic-published-on-invalid-date-with-activitypub/360228)._