Tom Kalbfus
Mongoose

Remember the show Voyagers, this little gadget was their time machine.
1.The first dial represents the date of the week.
2. The second dial is the latter half of the year-like the '13' in 2013.
3. The third dial is the first half of the year-like the '20' in 2013
4. The fourth dial is the month of the year.
This is the format, I would use for my fictional Omni the 315, Bogg had the 313. Omni stands for Omnichronometer in case your wondering
in the Omni 315
1. The first dial represents the date of the week, it is behind a glass cover, as it sets automatically depending on what date you enter on the three inner dials.
2. The Second Dial combines the Month and day of the year, there are 366 days represented to allow for leap years. If you set the date to February 29th in a non leap year the dial will automatically advance to March 1st when you press the green button, when the Omni is in manual mode. (More about that later)
3. The third dial is the second part of the year with numbers ranging from 00 to 99 twice the first time they are coupled with AD, the second time with BC.
4. The fourth dial is the century year, ranging from 0 to 19. (The third dial determined whether it is a century AD or a century BC. Now when you have the combination 0 and 00 AD this actually reads as 2000 AD, when it is set at 0 and 00 BC this reads as 2000 BC, as there is no year zero.
So the date range for the Omni model 315 is from 2000 BC to 2000 AD.
I was thinking that this might make an interesting Traveller campaign, mostly geared toward historical adventuring, mostly involved with putting history back on track.
Now why history goes wrong in the first place is an interesting question. I think the butterfly effect is involved, since we have a society of time travellers, the very act of going back in time can change history, even if there was no intent to do so in the first place.
Now the Voyagers are basically fixers, the question remains why their services are needed in the first place? One possibility is that time travel is used for other things besides exploring and interfering with history. One use is the terraforming of planets, as you know it can take from centuries to thousands of years to terraform a planet, well the society that created the Voyagers doesn't want to wait that long, so they send terraforming equipment into the past and they begin terraforming in the remote past so the planet is ready for colonization by the present, but unfortunately this has an unintended butterfly effect with Earths History, so the Voyager Corps was created to put right what once went wrong, and their headquarters is in the past, where they keep the original history, so when history changes the effect doesn't carry into the past. Lets place the Voyager Corps headquarters in the year 10,000 BC for good measure, most of the history is uptime from here. Most of the people in the Voyager Corps are clueless as the the purpose of their mission, as they are plucked from history as well.
The Omni has both a manual and an automatic mode. In the Manual mode, the red button on the right side of the Omni extends outward, when in such a position, you can manipulate the inner three dials surrounding the globe in the center, you can set the years, month and day, you can't set the day of the week, nor can you set the hour or minute of the day. the time in each zone is synchronized, that is if it was 6 PM local time when you pressed the red button it will be 6 PM local time at the time zone you arrive in, the Voyagers corps recognizes the need of its agents to adhere to a 24 hour diurnal cycle, and to avoid jet lag which would occur if you could set the time of day to different from the one you left.
In automatic mode, the red button on the right side of the Omni is depressed, if you press the green button on the left side of the Omni, it will take you to the nearest red zone, where history has gone wrong. When the red button is extended, you can manipulate the dials and travel to a time of you choice between January 1, 2000 BC and December 31, 2000 AD inclusive of these two end dates. if one Travels to December 31st and waits for the stroke of midnight, one can get to January 1, 2001, but any further use of the Omni after that will take you back within the range of January 1, 2000 BC Gregorian, and December 31, 2000 AD Gregorian. (The Voyager Handbook has a table for converting Julian Dates to Gregorian ones).
Oh yes for determining place, the globe in the center can be manipulated to determine position, when in manual mode, much as a touch screen is on an Iphone or Ipad.
What do you think of this idea for a campaign?