Today is minor palindrome and ambigram date i.e. 22.6.22. This can only be found on the small date stamps in post offices that opens on Sundays (mall post offices).
All the best in collecting another minor palindrome!
Here are the other palindrome dates for the rest of the year:
22.8.22 (also minor ambigram)
22.11.22 (also minor ambigram)
As there are post offices that open 7 days a week and with a combination of different states, should be able to get most of them this year!