Spreadsheet: 648496d1573065190-finding-week-number-based-on-custom-week-ranges-example-data
Sheet: Sheet1

Deal # | Close Date | Week # |  |  | Custom Week Number | Start Date | End Date | Calculated Week Number
1 | 2019-01-04 00:00:00 |  |  |  | 1 | 2019-01-01 00:00:00 | 2019-01-05 00:00:00
2 | 2019-01-27 00:00:00 |  |  |  | 2 | 2019-01-06 00:00:00 | 2019-01-12 00:00:00
3 | 2019-01-16 00:00:00 |  |  |  | 3 | 2019-01-13 00:00:00 | 2019-01-19 00:00:00
4 | 2019-01-03 00:00:00 |  |  |  | 4 | 2019-01-20 00:00:00 | 2019-01-26 00:00:00
5 | 2019-02-04 00:00:00 |  |  |  | 5 | 2019-01-27 00:00:00 | 2019-01-31 00:00:00
6 | 2019-02-18 00:00:00 |  |  |  | 6 | 2019-02-01 00:00:00 | 2019-02-09 00:00:00
7 | 2019-02-23 00:00:00 |  |  |  | 7 | 2019-02-10 00:00:00 | 2019-02-16 00:00:00
8 | 2019-01-31 00:00:00 |  |  |  | 8 | 2019-02-17 00:00:00 | 2019-02-23 00:00:00
 |  |  |  |  | 9 | 2019-02-24 00:00:00 | 2019-02-28 00:00:00
 |  |  |  |  | 10 | 2019-03-01 00:00:00 | 2019-03-09 00:00:00
 |  |  |  |  | 11 | 2019-03-10 00:00:00 | 2019-03-16 00:00:00
 |  |  |  |  | 12 | 2019-03-17 00:00:00 | 2019-03-23 00:00:00
 |  |  |  |  | 13 | 2019-03-24 00:00:00 | 2019-03-31 00:00:00
 |  |  |  |  | 14 | 2019-04-01 00:00:00 | 2019-04-06 00:00:00
 |  |  |  |  | 15 | 2019-04-07 00:00:00 | 2019-04-13 00:00:00
 |  |  |  |  | 16 | 2019-04-14 00:00:00 | 2019-04-20 00:00:00
 |  |  |  |  | 17 | 2019-04-21 00:00:00 | 2019-04-30 00:00:00
 |  |  |  |  | 18 | 2019-05-01 00:00:00 | 2019-05-04 00:00:00
 |  |  |  |  | 19 | 2019-05-05 00:00:00 | 2019-05-11 00:00:00
 |  |  |  |  | 20 | 2019-05-12 00:00:00 | 2019-05-18 00:00:00
 |  |  |  |  | 21 | 2019-05-19 00:00:00 | 2019-05-25 00:00:00
 |  |  |  |  | 22 | 2019-05-26 00:00:00 | 2019-05-31 00:00:00
 |  |  |  |  | 23 | 2019-06-01 00:00:00 | 2019-06-08 00:00:00
 |  |  |  |  | 24 | 2019-06-09 00:00:00 | 2019-06-15 00:00:00
 |  |  |  |  | 25 | 2019-06-16 00:00:00 | 2019-06-22 00:00:00
 |  |  |  |  | 26 | 2019-06-23 00:00:00 | 2019-06-30 00:00:00
 |  |  |  |  | 27 | 2019-07-01 00:00:00 | 2019-07-06 00:00:00
 |  |  |  |  | 28 | 2019-07-07 00:00:00 | 2019-07-13 00:00:00
 |  |  |  |  | 29 | 2019-07-14 00:00:00 | 2019-07-20 00:00:00
 |  |  |  |  | 30 | 2019-07-21 00:00:00 | 2019-07-27 00:00:00
 |  |  |  |  | 31 | 2019-07-28 00:00:00 | 2019-07-31 00:00:00
 |  |  |  |  | 32 | 2019-08-01 00:00:00 | 2019-08-10 00:00:00
 |  |  |  |  | 33 | 2019-08-11 00:00:00 | 2019-08-17 00:00:00
 |  |  |  |  | 34 | 2019-08-18 00:00:00 | 2019-08-24 00:00:00
 |  |  |  |  | 35 | 2019-08-25 00:00:00 | 2019-08-31 00:00:00
 |  |  |  |  | 36 | 2019-09-01 00:00:00 | 2019-09-07 00:00:00
 |  |  |  |  | 37 | 2019-09-08 00:00:00 | 2019-09-14 00:00:00
 |  |  |  |  | 38 | 2019-09-15 00:00:00 | 2019-09-21 00:00:00
 |  |  |  |  | 39 | 2019-09-22 00:00:00 | 2019-09-30 00:00:00
 |  |  |  |  | 40 | 2019-10-01 00:00:00 | 2019-10-05 00:00:00
 |  |  |  |  | 41 | 2019-10-06 00:00:00 | 2019-10-12 00:00:00
 |  |  |  |  | 42 | 2019-10-13 00:00:00 | 2019-10-19 00:00:00
 |  |  |  |  | 43 | 2019-10-20 00:00:00 | 2019-10-26 00:00:00
 |  |  |  |  | 44 | 2019-10-27 00:00:00 | 2019-10-31 00:00:00
 |  |  |  |  | 45 | 2019-11-01 00:00:00 | 2019-11-09 00:00:00
 |  |  |  |  | 46 | 2019-11-10 00:00:00 | 2019-11-16 00:00:00
 |  |  |  |  | 47 | 2019-11-17 00:00:00 | 2019-11-23 00:00:00
 |  |  |  |  | 48 | 2019-11-24 00:00:00 | 2019-11-30 00:00:00
 |  |  |  |  | 49 | 2019-12-01 00:00:00 | 2019-12-07 00:00:00
 |  |  |  |  | 50 | 2019-12-08 00:00:00 | 2019-12-14 00:00:00
 |  |  |  |  | 51 | 2019-12-15 00:00:00 | 2019-12-21 00:00:00
 |  |  |  |  | 52 | 2019-12-22 00:00:00 | 2019-12-31 00:00:00