https://www.youtube.com/watch?v=it5iytzdetg
long torah codes about purim esrter mašijah ben josef elijah koreš
now 5781 to me it start at 17.3 first day of aviv according to chanoch because on the 16.3 is day and night time equinox so 5781 purim will be in late februara 2022 on catholic calendar.