Time Sea Power
See timeanddate.com Zulu vs Lima Military Time Zones with current time. In short, Z ie ZULU is UTC, the only time format that matters in this planet ;)
In mission editor on the Scenario tab, on the global map view, if you move the black icon for latitude/longitude it wont change anything, however when you move your UNITS around, that will change LIMA (L) local military time zone of your mission. However LIMA time zone is tied to the black lat/lon anchor icon, so you should move that to where the center of your mission/scenario location is.
When playing Sea Power you can find the game time, clock, in (almost perfect) UTC format ISO 8601 (and utctime.net) displayed in top right corner of the graphical user interface (GUI).
This is ZULU military time zone (same as UTC) indicated by Z character in Sea Power:
And on the same mission once I click the time numbers anywhere on the line, it changes to LIMA local military time zone indicated by L character, also note how the actual time changes.
Remember that in your mission, in the area you chose, where your units and the lat/long icon is located, the time will be most likely different than in my above example images. I mean the difference between 12 and 11.
Its a wonderful thing that Sea Power is using ZULU and LIMA time zones, gives you that cool military mood right off the bat :)
Mission developers can change the date and time of the mission they are creating, so just to be clear there is no reflection on any real life clocks/time with this in-game time, I mean you can pause game-time so should be a dead giveaway there.
Sea Power defaults to ZULU time, meaning the ISO 8601 time string ends with Z character.