> When people did resume work on the same day, it took an average length of time of 25 min. 26 sec (sd=54 min. 48 sec.).

From the Gloria Mark paper: https://ics.uci.edu/~gmark/CHI2005.pdf

That's the paper source. And the researcher when interviewed verbally gave a slightly different number in the same ballpark of 23 minutes and 15 seconds instead of 25 minutes and 26 seconds.