All functions / Date & Time
EOMONTH
The last day of the month, a number of months away.
Syntax
=EOMONTH(start_date, months)
Arguments
start_date: The starting date.months: 0 for this month, 1 for next month, -1 for last month.
Example
=EOMONTH(A2, 0) → Last day of the month in A2