More boxes hatching and clutches dont get any smaller

I checked some more boxes tonight on Mr and Mrs Piper's land. The first image shows the setting for the boxes -

 

This image shows 1 day old Blue Tit chicks in Box P 01. I've recorded them as 8+. The box had 9 eggs and I think I can see 9 chicks but I've erred on the cautious side for a few days.

 

 

Even heavily cropped I'm undecided - 8 or 9?

 

 

Box P 03 had 7 Great Tit eggs, all have hatched and are shown here probably 3 days old

 

 

and once again, heavily cropped

 

 

This one is an oddity. Adult Blue Tit in the box on Sunday, one egg. I assumed it had been laid that day. Tonight the same, bird incubating one egg! Problem is now, I cant work out when it was laid in order to work out the hatching date.