I’d say the timestamp is stored in UTC then the application / business logic needs to understand what the user’s local time zone is and convert it to whatever local time it is based on that user’s setting. It’s not really a Nostr thing, though, an application thing
Discussion
It’s been a while since I’ve looked at the spec, but I’d say probably make most sense to store this in the metadata / profile event if you were to do it only using Nostr otherwise a db to support application specific logic
Thank you, nostr:nprofile1qy28wumn8ghj7cnzvgh8xctww3hhxtnvdakqz9thwden5te0v4jx2m3wdehhxarj9ekxzmnyqqsymxft68sj7auxvv6vu07lugpqx7vmlmacfdldtng3z2grg52hkkstwet4m! Now nostr:nprofile1qy88wumn8ghj7mn0wvhxcmmv9uq37amnwvaz7tmwdaehgu3dwfjkccte9ejx2un9ddex7umn9ekk2tcqyqlhwrt96wnkf2w9edgr4cfruchvwkv26q6asdhz4qg08pm6w3djg3c8m4j has more on his to-do list 😉
PRs welcome 🤗