Rev 12:1 - 6
There are many scholars who believe this is actually about past events. Specifically: The birth of Jesus on Sept 11, 3 B.C.
I'm not going to do a detailed explanation any justice, so I'll give you the cliff notes version. Michael Heiser very eloquently explains it in "Reversing Hermon".
They calculated where Virgo would have been in the sky to make her clothed with the sun. The narrowed this event down to a 20 day window.
Next, the moon under her feet narrows the time window down even further - a 90 minute period.
They also analyzed the star seen by the Magi in Matt 2. This is Jupiter retrograde motion & it was taken into account for the date I listed as well.