Is there a way to produce a sum according to date time stamp values of another column on excel

Question

I have a CSV file of rain gauge data, with the following example format:

No.    Date/time.           Rainfall
1.     01/21/22 03:13:56    0
2.     01/21/22 03:14:56    0
3.     01/21/22 03:15:56    2.1
4.     01/21/22 03:16:56    1.4
...

Is there a way for me to resample this data to produce a daily sum? A formula perhaps?

Answer 1

Assuming the input data for the second column is in date format, you can use the following formula if you prefer it to a Pivot Table:

=LET(B, INT(B2:B7), C, C2:C7, ux, UNIQUE(B), 
 m, MAP(ux, LAMBDA(x, SUM((B=x) * C))), VSTACK({"Days","Total"}, HSTACK(ux, m)))

Here is the output.