[sd], [sddd], [sdddd] : Conditional Day Tokens
Use the token [sd] (and related tokens) if you wish any of the day tokens to appear only on the first of the month ('s' means 'start'). On other days the token converts to a blank. Note that this is not a zap token. Blank means no text.
On Thursday June 1st :
•[sd] = 1
•[sDDD] = THU
•[sDddd] = Thursday
On May 3rd, [sd], [sDdd], [sDddd] are all blank.