Your help greatly appreciated (first posting to a forum)
Scenario
One workbook; two worksheets. The second worksheet contains, across multiple columns, the results of formulas in multiple rows (corresponding to rows in worksheet one – ‘shifts’). The formula (referenced) is =IF(AND(I$1=shifts!$J3,I$1<shifts!$L3),"1","0"). This places either the value ‘0’ or the value’1’ in a referenced cells. The column headings are from 06:00 hrs to 24:00 in 15 minute increments.

The sheet contains columns to the left with codes (either ‘F’; ‘1’; ‘2’ and so on). At the bottom of each list of 15 minute columns containing the formulas (which shown the results – either ‘0’ or ‘1’) I want to add up using =SUMIF(Mon!A2:A10,"F",Mon!I2:I10), which refers in this case to code ‘F’, all the ‘1’s’ where ‘F’ is the code.

This works satisfactorily in a test sheet where ‘0’ and ‘1’ are entered manually but not when these values are the results of the IF/AND formula.

I have prepared a cut down Workbook with some actuals in it if required and also have typed illustration to put here if required (but thought might be too much - this being new to me and not wanting to upset).

Been looking on many sites for solution over past days. 22:00 signing off until tomorrow after work. In anticipation and gratitude.