I use to automatically tag my e-mails with time based labels, on Gmail. Can I simply use filters? Maybe yes, but I didn’t get to make them work when specifying only dates as criterias. Maybe I’m idiot, but Gmail simply doesn’t allow me to specify such filters. So I tricked him with a small Google Apps Script, that tags emails with a current year and a current month nested labels. Please note that it just works for 2017 and month names are in Italian. I scheduled it to run once a minute.
Are there more efficient ways to do the job? Of course. Could I have written a better code? Of course. But it just works after five minutes of scripting. Feel free to use it if you want.