Just heard this 10 minutes ago
Why don’t we push off taanis Esther if we can’t do it b’zmano, just like you’d push off other fast days? We don’t want sad days to be pulled up, it should be pushed later.
Reason is bc taanis Esther is not a sad day. It’s a reenactment of the neis of Purim. That the yidden fasted and did teshuva, and the yeshua came. So too by us we are doing the motions of teshuva to receive the yeshua.
Taanis Esther is the beginning of the simcha of Purim
It’s the Ritva snd other rishonim. At least the teshuva part, not the simcha part. The Maggie mishna learns it’s a practical reason because Friday, Shabbos and Sunday don’t work out to fast.