Universal credit savings questions

once out of the capital transitional protection for Universal credits these below questions are in relation too.

1) so our assesment period is between 29th and 28th of every month.
So the last day of our AP is the 28th of every month? Regardless of if its a Sunday or Monday etc? Correct?

2) So for example during the course of the AP we are below 16k but then wages come in, UC credit comes in, other benefits come in which takes us over 16k. Then by the last day if the AP we are back under 16k after expenses etc are paid then we do not need to declare any changes as there has been no changes in savings being over 16k? Is that correct?

3) the same situation as above (2) for example are at £15,800 and a random gift from a relative comes in for £300 takes us over 16k but again we are still under 16k by the end if the AP does the same still apply as above (2) no different, even though it was a gift and not benefit/wages that took us over 16k?
As I had read that its only savings or wages that are disregarded as capital?

For example we get a gift from my mother for my birthday of £300 and we used it just in general living expenses and that £300 pushed us over 16k but we had spent it before the end of the AP and we were back below 16k by the end of the AP what happens in this situation?
Does the DWP still consider us above 16k and that £300 birthday gift now added to our savings even though it's been spent on general living expenses?