I can empathize. I've always found date-related bugs to be the hardest to track down and messiest to resolve. Especially in applications consuming data from a huge variety of buggy input formats ("So it's a server in Australia, but their application layer adjusts time +36000 seconds and their durations are listed in days, but it's daylight savings here...")

"Well, just don't fly the shuttle over New Year's" seems like a reasonable enough workaround for an otherwise highly planned out program, especially when, as a commenter in OP points out, the missions were only intended to run weeks at a time to begin with.

Agreed. If that's not an example of YAGNI I don't know what is.

And that it would take millions of dollars to fix.