Imagine each system runs ina different time line. This is shown by the 'stardate' at the top of the screen - ie the turn the system opened, and the current turn within the system.
443.447 means the systems opened in turn 443, and there have been 4 turns since then.
When you submit orders they are stored against the ship in the DB. When a system processed the turn report will contain that systems new positions, AND any orders you have submitted for ships in other systems already. i.e. it remembers the orders, and you do not have to resubmit.
The galactic map is a special case, processing once every 8 hours only.
And it was a sod to code.