The last & the first day of a month in Google Sheets

Question

How to get the first and last day of the previous month in Google Sheets?

Answer 1

If you had your base date in A1,
this will return the date of the last day of the previous month:

=eomonth(A1,-1)

For the date of the first day of the previous month, this is the shortest way:

=eomonth(A1,-2)+1

Also possible:

=date(year(A1),month(A1)-1,1)

Answer 2

for the last day of the previous month (international)

=eomonth(now();-1)

for the last day of the previous month (USA)

 =eomonth(now(),-1)

for the first day of the previous month (international)

=eomonth(now();-2)+1

for the first day of the previous month (USA)

    =eomonth(now(),-2)+1

Demo:

Answer 3

Use =eomonth((eomonth(today(),0)),-2)+1 for use when you want previous from today.

For the last day of the previous month, use =eomonth((eomonth(today(),0)),-1).