Sum by week of the year

[phitho]

Ok this might be a good one....

I have a sheet with employee names, time worked, and dates on which the work was completed. Is it possible to have Excel calculate the total time worked by an employee (lets use John as a name example) by the week of the year?

For example, the week starting on 3/5/2018 (March 5, 2018) is the 10th week of the year (according to ISO standard, see this webpage: https://www.epochconverter.com/weeks/2018), the formula would calculate for that week. This is something I want to do rather than constantly having to modify my between ranges, I would just change the week number...

 

[PaddyD]

you could add an extra column populated with weeknum() and use that, e.g. to drive a pivot table.

 

[AhoyNC]

Take a lookup at the ISOWEEKNUM function.
You could then use a helper column and do something like Table 1 or if you don't want a helper column then something like Table 2 in example below.

Excel Workbook
	A	B	C	D	E	F	G	H	I
1	Name	Date	Value	Week #		Table 1
2	John	2/1/2018	1	5		Week#/ Name	John	Sam	Mary
3	Sam	2/8/2018	2	6		5	1	0	0
4	John	2/9/2018	3	6		6	3	2	0
5	Sam	2/16/2018	4	7		7	0	4	0
6	Sam	2/23/2018	5	8		8	0	5	0
7	Mary	3/7/2018	6	10		9	0	0	0
8	John	3/10/2018	7	10		10	15	0	15
9	John	3/10/2018	8	10		11	0	10	0
10	Mary	3/11/2018	9	10
11	Sam	3/18/2018	10	11		Table 2
12	Sam	3/19/2018	11	12		Week#/ Name	John	Sam	Mary
13	John	3/26/2018	12	13		5	1	0	0
14	Sam	4/2/2018	13	14		6	3	2	0
15	Sam	4/9/2018	14	15		7	0	4	0
16	John	4/16/2018	15	16		8	0	5	0
17	Mary	4/23/2018	16	17		9	0	0	0
18	Mary	4/30/2018	17	18		10	15	0	15
19	John	5/7/2018	18	19		11	0	10	0
20	Sam	5/14/2018	19	20
21	John	5/21/2018	20	21
Sheet

 

[PaddyD]

"Take a lookup at the ISOWEEKNUM function."

On reflection that would have been a better suggestion than mine, given the actual question