I always wind up getting out my epoch calculator when I run my weekly music trivia night on thursdays on my discord server at SamuraiZ. And it's annoying to tab away and convert and figure ut GMT/UTC and what timezone, so I figured I'd come up with a bot that takes care of that where you just enter in your localtime what time something is at. It spits out the epoch time, which discord uses for the UTC, which it then will convert into each user's localtime. Basically I obviate most of the timezone stuff using python's "date" library functionality. This runs locally.
I tried some others, but most of them don't even have basic errorchecking. This has the leap year algorithm and related validation and checking implemented. I'm sure there are still some problems, but I ironed out most of them. The token is naturally omitted for security reasons. If you've never set up a discord bot before, you have to do that with discord and they give you a token which is basically another username/pw. You can go here: https://discord.com/developers/applications
Also, hosting in another timezone may affect the local time functionality and you'd have to use the local time of the server or re-write using datetime and non-naive datetime objects which is somewhat more complicated.
The timestamper bot uses discord.py (which you can find here https://discordpy.readthedocs.io/en/stable/index.html and on github here https://github.com/Rapptz/discord.py) and the discord API. Takes a time in your localtime in 24H time mm/dd/yy and converts it to a discord usable epoch timestamp in the format <t:xyz > which can be easily copypasted and a verification next to it. The only library I used was python's "time" besides "discord" and "asyncio" which you need for a discord bot. datetime actually makes it more complicated with timezones and naive and non-naive functionality. Has an algorithm that accounts for leap year and related to prevented odd errors. Credit me if you use it. Feel free to message me with questions.
MIT license.
Have fun!
1.0.1 updated due to minor difficult to reproduce non-fatal error regarding initialization at some localtime with certain user input or where initialization prior to user input fails to occur. Since year element passed by reference and not value, addition of 2000 may lead to improper detection as overlong. Subtraction of 2000 added before return statements in 3 locations. This solves. Did so rather than refactoring and altering any progam logic, though I may do that in the future if time allows so year is xxxx. Which in hindsight xxxx year for length of year variable may have been a superior choice due to leap year algo.