How long is a goldfish in labor for?

Goldfish do not come into 'heat' they simply come into breeding condition around springtime. Provided they are in a large enough tank/pond and all the other requirements are met regarding their health and condition they usually spawn when temperatures rise to around 70F-75F. If for some reason they do not spawn but have been in condition to do so, once conditions no longer suit spawning (variable time) the ova are absorbed back into the fishes body.