[feature] Jinja2 filter for converting Unix timestamps into human-readable datetime in notifications #3641
Description
Version and OS
0.45.x (Docker)
Is your feature request related to a problem? Please describe.
Some monitored pages return timestamps in Unix format (e.g. 1759188682) rather than human-readable dates.
When the notification uses tokens like {{diff}}, {{triggered_text}}, or {{current_snapshot}}, the timestamp is included as a raw number, which makes notifications difficult to read.
Currently there is no way to convert Unix timestamps to formatted datetime values using Jinja2 inside changedetection.io.
Describe the solution you'd like
A built-in Jinja2 filter to convert Unix timestamps into readable dates. Example:
{{ triggered_text | unixtime }}
Or with formatting support:
{{ triggered_text | unixtime("%d.%m.%Y %H:%M:%S") }}
This would allow timestamp conversion directly in notification templates without requiring external processing.
Describe the use-case and give concrete real-world examples
Many API-style pages and structured responses expose timestamps like:
last_battle_at: 1759188682
Expected output in a notification:
Last battle: 30.09.2025 02:31
Right now achieving this requires a custom webhook or external automation simply to convert the value, which is excessive for such a basic transformation.
Additional context
- Jinja2 currently has no timestamp conversion
- Existing filters (tojson, urlencode, etc) do not help
- External middleware (Node-RED, n8n, proxy scripts) works but is overkill for this use case
- A small built-in helper would greatly improve readability for timestamp-based content
- Even a documented workaround would be helpful if a filter cannot be implemented
Thanks!