Merge entire rows with same date based on column O and put week number of the year

I've never made one macro from scratch but I am hoping for some input on how to go about making this happen.

Attached are two file, one with source file and the file with results.
1- It sort by ETA (column O) from oldest to newest. At the same time and as a second level, it sorts by ItemNUmber (column I)
2- It put thick outside borders for each ETA
3- In column Q is the week number (a week is from monday to sunday). If the ETA in column O falls in monday and tuesday, the Week number must be that week e.g. if it was Sep 19th, it sould be W38, but if ETA falls in wednesday or after, the Week number would be in this case W39.

Note, rows may vary also there are three segments ONLY Asia, Americas and CAD. These may be more than only three. Between each segment e.g. Asia and Americas we may have 3, 2 o more empty rows, they vary.
Both file does not have the exact information, I simply added them as examples.

Thank you,