Allow to use custom start date/datetime in PYSON
With ir.date, we allow to customize the "today". But in PYSON Date and DateTime are evaluated by hard-coded today/now.
I think we should allow to define another starting point as an PYSON.
This instance will be upgraded to Heptapod 1.3.1 (GitLab 16.9.3) on 2023-03-28 at 17:00 UTC+1
With ir.date, we allow to customize the "today". But in PYSON Date and DateTime are evaluated by hard-coded today/now.
I think we should allow to define another starting point as an PYSON.