Using lookup start and end date for Gantt blocks

Hello,
We are developing apps and I would like to use Gantt blocks to follow the development of functionalities.

functionalities are distributed in sprints which have a stat and end date.

in the functionalities table, I have a lookup with the start and end date (coming from a sprint table).
unfortunately, when I use this data, the gantt does not see the dates (even with proper formatting option of the lookup fields).
Same if I use a function field which display the lookup field.
I have to manually change a date field Start and End to see the gantt.
Any idea how to solve this ?
Thanks in advance

Keep in mind formatting is just that: It changes the presentation of the data, but not the underlying value.

Do you mean you have a formula field configured the with function {LookedUpDate}? If so, Airtable is seeing that as 1 January 2019 (or whatever the year is in the date). Presumably this is because of the way it handles array values: The lookup field is technically a single-element array of dates rather than an actual date. Try

DATETIME_PARSE({LookedUpDate}&'')

That will force the field into proper internal datetime format and make it correctly accessible to the Gantt Block.

I want to visualize a set of features by release milestone, and the correct place for the dates is in the milestones table. It seems the solution here is to use a lookup to get the actual date info, then add a (presumably hidden) field with a formula parsing the date out of that lookup field?

That’s rather clumsy, especially given that the documentation for the Gantt block indicates that it supports calculated fields. Can we expect any improvement on this in the near term?