Linux gets the first second of last month and last second of last month

Because the need to write the script needs to get the first second of last month and last second of last month, consult the relevant information, and through their own practice, found the following method can meet the requirements, in this note, if there are other good methods, please leave a message, I will be grateful!

Get the first second of the month:

Date-d "' Date-d" last month "+%y%m01 ' 00:00:00" "+%s

Get the last second of last month:

Date-d "' Date +%y%m01 ' 23:59:59 ' last Day" +%s