There is currently the risk of posting something with a date that isn’t in the period (which I understand some practices actually want to do?). For others, making sure you don’t end up with discrepancies between period totals and date totals, allow the practice to set that whatever date is entered for the item you are posting (e.g. an invoice) and it will automatically post this into the correct period based on the date (rather than asking you to choose the period). You could set this as a practice option to turn on and off.
I would be very happy with this, or at the very least for there to be a warning where there is a mismatch between the posting date and the selected period.