Why are you creating a problem where there is none
both shifts start on the same day,so why not count their production as produced on that day
(what you already seem to be doing judging by your Type DailyProduce)

but if you want to hairsplit:
just have the nightshift make 2 entrys(records) in the table on the last day of the month
(1 for the last day and 1 for the first day)