Jiffy peat pot windowsill greenhouse seeds might have dried out

How long does it take for the seeds to pop out from the soil because my friends think my jiffy pots got dry not sure how dry my friend normally keeps it more moist though do you think it would be fine even if it had just a little bit of moisture as long as it wasn't bone dry?
.Even though it had a humidity dome it dried a bit..I think it was 8 hours or 2 days that he didnt water it he was using a jiffy 7 windowsill greenhouse he sees the seed sprouts but it has not opened to reveal the cotyledons.It was taproot down by the way.Its just it hasn't gotten any longer above ground in a day.
Is it possible it died?
How do you know if the jiffy has become dried.
How do you define dry in germination?As in Bone Dry?

its dead. That seed didnt have the energy (for some reason ) to sprout. Also dont let jiffy dry out at this stage. Once it has sprouted and shows leaves ,then they can dry about 50%. So if it dried out during germination, its dead.