Anniversaries: date off by one

[techAPJ (Arpit Jalan)]

@techAPJ

I am in timezone UTC+5:30 but have an offset of 6 hours, so I am seeing few edge cases for users who created account between 23:30 and 00:00. Looking into it.

Fixed via:

https://github.com/discourse/discourse-cakeday/commit/24aa36e49ed484ae536dbf8cea2aef826786622d