From my understanding Baserow breaks up the content of the concat formula into various parts (I believe Baserow uses Abstract Syntax trees in the backend to manage this structure) and calls each part’s appropiate to_text function
From their Github
" - All transformations of the formula that occur during the typing process
have been applied. For instance if you have the formula concat(1, 'a', field('a date field')) during the typing process the
concat function will wrap all of its arguments in the appropriate to_text
function if they are of different types. This internal formula will
then look something like concat(totext(1), 'a', datetime_format(field( 'field_NN', 'YYYY-MM-DD'))
Here is the link
So I belive what may be happening is internally Baserow is calling the datetime_format (with some default values??) and your date is getting messed up as a result
You might try calling the concat function with the datetime_format explicitly mentioned (with the appropriate parameters to datetime_format). It might get you the results in the format you are wanting.
yes, it has to do with timezones.
Datetimes are always saved in UTC in Baserow. The web frontend converts the datetime value in the user timezone unless the “Set timezone for all collaborators” has been set at a field level.
Anyway, as @Harsh correctly reported, at the moment the datetime_format formula cannot format dates into a different timezone than UTC.
The default behaviour of totext (the formula used to concat dates) is now looking for a timezone in the field settings, so if you set a timezone for all the collaborators in the field you’ll be able to format the date in the expected timezone.