How soon after the new moon can you spot the thin crescent moon against the bright backdrop of a twilight sky?
Cases of unaided-eye sightings of the moon when it is younger than 24 hours are not very common, and sightings within 20 hours of a new phase are very rare. The best opportunities usually come in February, March and April, for at these times the lunar crescent stands directly above a sun that has just set.
