Which date function advances a date, time or datetime value by a given interval? | SAS Programming

INTNX: INTNX function advances a date, time, or datetime value by a given interval, and returns a date, time, or datetime value. Ex: INTNX(interval,start-from,number-of-increments,alignment)
INTCK: INTCK(interval,start-of-period,end-of-period) is an interval functioncounts the number of intervals between two give SAS dates, Time and/or datetime.
DATETIME () returns the current date and time of day.
DATDIF (sdate,edate,basis): returns the number of days between two dates.