Do bitches always give birth during the night??

no mine dont. Infacr my recent litter was the closest I have come with digging and pacing all night and then pups born starting at 5:00am. Other litters have started at 2:00in the after noon and 12:30 lunchtime.

Mine wait till all goes quiet including my noisy neighbours, they can have been in labour from the morning but be nearly midnight before the first pup appears.

My girl had hers at 6.30pm and 9.30pm, very civilised!

most of our litters have been in the day :) bu ive had them go thru the night when its been a big litter

Mine do seem to like the early hours of the morning.  :-)

Our bitch had pups 10 days ago... had first one at about 5pm and number 9 at 9.15pm. My other litter (a long time ago) was about 7am but I was up all night!

In my expereience they are totally variable.

I've only had one litter in normal hours LOL. All of my others have been around the 2-3am hours.