Active formula that reads dates and compare them with week sheets

[Ramzes]

Hello,

I have got a problem with a formula to be active.
What I mean is:
I want a formula to check for today's date then compare it with the week it is in and make that as the last sheet (each named as "Week _ _") and sum all the quantities since the vehicle numbered in each date on the left.

I did attach a sample file which only have 1 sheet with week name, but as time goes on I will be adding the sheets into the document and all of them will be named with consecutive week number (Week 12, Week 13, etc.).

I was thinking about vlookup and match functions for calculations only but I have no idea what I can use to make it read the dates and compare them to the sheets with the relevant week numbers.

Any suggestions appreciated.

Thanks for having a go!
Simon