What specific departments/offices and opening times?
The Motor Tax Office is one I can think of.
The desks for all motoring issues is open from 10-12 and 1.30-3.
Considering most peoples lunch is 12-1 or at a strech, 1-2 and factoring in the travel to get there during a busy time of the day, I'm amazed that it's open at all.
I know you can get tax online but there are ties when you need to get stuff done manually and it can be a pain !
On a lighter note (an this always makes me smile when I think of it) I used to work in Revenue many moons ago and a taxpayer rang the office one day and the operator wasn't sure which extension to put them through to so rang a number in that section to find out. The caller was from Claremorris so the operator asked a staff member ( a particularly useless staff member btw) and got the reply "Oh there's no Claire Morris working here"