Not Seeing all dateField options when creating Calendar View

Hello,

I am trying to use the calendar view. I have many formula fields that are calculating different dates. I am only seeing two of those listed here. Is this a bug? Or is there something in the formulas that is making it not appear as a date?

here are the two formulas that do show up in the list:

  1. SET_TIMEZONE(DATEADD(DateOfReply, -1, ‘days’),‘America/Pacific’)

  2. IF(HOUR({DateOfReply_Pacific}) >=20, DateOfReply, PreviousDay_Pacific)

And here is one that I need that isn’t showing up:

  1. IF(HOUR({DateOfReply_Eastern}) >=20, DateOfReply_Eastern, PreviousDay_Eastern)