Forum Discussion

Copper Contributor

Sep 02, 2023

Solved

Calculate downtime

Hello all, I am looking for help. I would like to calculate the downtime of a machine in Excel. for this I need the difference in minutes between the start time and stop time. The only excep...

excel

Formulas and Functions

Patrick2788

Sep 02, 2023

tomvermaas

This is a 365 solution. I've created a function called Downtime.

Downtime(Start,Stop)
=LET(
    Min_in_day, 1440,
    one_minute, 1 / Min_in_day,
    TotalMinutes, LAMBDA(begin, end,
        LET(
            duration, (end - begin) * Min_in_day,
            TotalTime, SEQUENCE(duration, , begin, one_minute),
            hr, TotalTime - INT(TotalTime),
            Actual, FILTER(
                TotalTime,
                (WEEKDAY(TotalTime, 2) < 6) * (hr >= 6 / 24) * (hr < 23 / 24),
                0
            ),
            SUM(SIGN(Actual))
        )
    ),
    MAP(start, stop, TotalMinutes)
)

DownTime.xlsx23 KB

javier04

Copper Contributor

Jul 23, 2026

Great solution from PatrickZ788! The LAMBDA approach handles the Monday-Friday exception cleanly.

One thing worth adding — before building out the full formula, it helps to manually verify a few of your downtime calculations first using a simple Calculadora Alicia to confirm your expected minute differences are correct. That way you can validate the formula output against known values during testing saves a lot of debugging time when working with time-based calculations in Excel.