FIRST_DAY_OF_QUARTER

Returns the date of the first day of the calendar quarter (1 January, 1 April, 1 July or 1 October) that the provided date falls in

FIRST_DAY_OF_QUARTER (date)

Attribute of the Date type or date constant or calculation producing a date

Date: the first day of the quarter of the provided date

IF FIRST_DAY_OF_QUARTER (Account.OpeningDate) = 01/10/2004 THEN ...