In my estate in Lucan, we usually get no post during the week and then Saturday morning a glut of stuff. I queried it with our postman in work, as he lives in lucan and he told me due to staff shortages, its delivered on Saturday by someone doing overtime.
Even if post arrives during the week, its usually at about 4.30 in the afternoon. We all booked in for a staff medical at work. Everybody else got theirs the next day/day after and mine took about a week to arrive, even though they were all sent out the same day.