Failed AttemptsThe Matriarchal Eden have mentioned a few attempts to create a single way of measuring time across the galaxy, but these attempts failed for a myriad of reasons. Some failed due to conflicting opinions of which measurements to use or how long they should be. The main reason, however, is that the universe seems to be against the idea, entirely. Imagine us colonizing another world, light years away from Safeharbor. These two planets would use the same time zone or, at least, be easily able to convert time to their own time zone. If a ship traveled using only fusion engines traveling from Safeharbor to this new world, and used the same manner of keeping time, the clocks won't line up. The faster you travel, the faster time ticks around you. The crew of this vessel would likely expect a pat on the back, as from their perspective, they arrived early. No matter how you look at it, time is merely a measurement of change, and it's impossible to get everyone synced up.
How does time work?
It doesn't, and it's a fact of life we have to accept. We use our own methods, and everyone else uses theirs. It's confusing, which leads to misunderstanding and unintentional frustration, but it's a fact. The best we can do is account for dilation, but this must be done with every new location, every new timezone. What is a year to us may be months, or decades to others. As such. The best course of action is to rely on your own understanding of time. A general idea of a day can be enough to get your point across in conversation, as can any measurement of time. You know what it feels like for a day to pass, but again, time is relative. What feels like minutes to you could feel much longer for others. It's inefficient, it's messy, and it's impossible to be precise, but it's all we have. I wish I had a better answer for you, but that's just how it is.
The major issue with time, at least for me as, is how it differs from individual to individual. Some say the The Battle of The Pillars and The First War occured years ago, but I clearly log it as an event from two years ago. This problem is only made more complicated in that some battles from the first war are still being fought between the Eden and siliue ships that have yet to receive the news. Space is big, and it may be that events do not have a clear start and end. The war ended here in recent memory, while for others, it still rages on. For others still, it never occurred in the first place, and in some places, happened much earlier than we know. It's best not to worry about it. Time isn't that important when on the verge of extinction, anyway. Take it at face value, for your own sake. The stress could lead you to an early grave, or perhaps a late one...