Time
From A Wiki in the Desert
If your timezone is set correctly in game (so it shows up accurately on your in-game calendar) you can use this format to convey a time to people from other timezones in game.
{time:xxxx}
Where the xxxx is your time in 24 hour numbers in your own timezone. So if I have an event starting at 11am my time I type {time:1100} which then shows up to other people as <12:00> if they are 1 hour ahead of me or <10:00> if they are one hour behind me.
There may be problems when attempting to do this across the dateline.