"It may only seem like a matter of hours
since your last battle here, but remember
that seventeen years have passed for those
of us who did not spend the voyage from Tau
Ceti in a stasis chamber. A few things
have changed:"- Durandal, referring to Boomer, Marathon 2, chapter: Durandal, level: If I had a Rocket Launcher, I'd Make Somebody Pay
Now, if I recall, it was 17 years since your last battle on the Marathon at this point, not Boomer. It had only been a few hours since the last fight on Boomer, which was the beginning of Marathon 2. Saying yet another 17 years had passed would put us past Durandal's estimated time of the universe's collapse.