Mine does it that way. There are columns off the right hand end of the page, set to zero width, with "IF" statements comparing the date in column 1 with the date now, and showing the hours from column 10 if the difference <31 or <91. Those columns are totalled, and the total appears in the box at the bottom of the logbook.
The same principle counts landings (just in case), Instrument approaches, and suchlike.
It's not elegant, but I understand it and it works.