In The Forever War by Joe Haldeman, there is extensive discussion of how Mandella decides
to wait six days after deploying the nova bomb outside the stasis field before they leave the field.
He estimates how long to wait as 5 hours to 6 days, and another character estimates 4.5 hours to 5 days, but Mandella is in command so he decides six days (he gets the only vote).
So after going through all the discussion of how long they should wait, I don't see how they would be able to tell five days from six days anyhow.
Electronics don't work in the stasis field and they can't get any signal from outside. Did I miss something? What's the explanation?