Microsoft Excel tutorial on how to count records by week.
This video includes three methods:
Using Group Field in a pivot table to roll up to weeks.
Using a formula of Data minus WEEKNUM(,3) to back the date to Monday.
Using ISOWEEKNUM plus the year along with SORT, UNIQUE, and COUNTIF.

To download the data, visit: https://www.mrexcel.com/youtube/GLkEsvirk9Y/

Table of Contents
(0:00) Count by Week in Excel pivot table
(0:43) Pivot convert dates to weeks
(1:33) Using date minus WEEKDAY(,3)
(2:19) Sort, Unique, COUNTIF
(2:53) Using ISOWEEKNUM in Excel
(3:30) Excel formula for Year and Week Number