Hi Jimmmy.
Please accept my apologies for considering you to be a potential spammer on your other thread. (We get loads of them here and they're getting ever more cunning).
The Roman Catholic church seems to be happy to
start Sunday a bit earlier than everyone else. (Quote: "Since the Second Vatican Council, the time for fulfilling the obligation to attend Mass on Sunday or a Holy Day of Obligation now begins on the evening of the day before, and most parish churches do celebrate the Sunday Mass also on Saturday evening". Source:
https://en.wikipedia.org/wiki/Mass_in_the_Catholic_Church#Time_of_celebration_of_Mass ).
However I'm unaware of anything which seeks to end it any earlier than elsewhere. My friend is a practising RC and he always arrives at the pub on a Sunday evening after coming from Benediction, so he's definitely still 'being religious' well after noon.
I suspect that the 'information' you've been given relates to the idea that Catholics believe that they're absolved of all sin once they've given confession which, prior to Sunday Mass being allowed to occur on Saturday evenings, would typically probably have occurred around midday on a Sunday. That would mean that they 'started with a clean sheet' on Sunday afternoons (which isn't quite the same thing as being free to sin though!)