Are there C++ libs that use floating points for timestamps? I was under the impression that most stacks have accepted int64 epoch microseconds as the most reasonable format.
Couple decades ago Microsoft did that too, VT_DATE in old OLE Automation keeping FP64 value inside. Luckily, their newer APIs and frameworks are using uint64 with 100-nanoseconds ticks.
Don't have a publicly visible reference to give at the moment, but it's still sometimes seen where relative timestamps are being tracked, such as in an audio library tracking time elapsed since start. It's probably less used for absolute time where the precision problems are more obvious.
LONG_MAX nanoseconds is just Friday, April 11, 2262 11:47:16.854 PM, not exactly a future-proof approach. I guess having Tuesday, September 21, 1677 12:12:43.145 AM as the earliest expressible timestamp neatly sidesteps the problem of proleptic Gregorian vs Julian calendars.
