Unix time 1666666666 happened last month, on October 25th 02:57:46 UTC.
A closer "round" number will be 1670000000, happening next month on December 2nd 16:53:20 UTC.
But for 1700000000 we'll have to wait until next year, November 14th 22:13:20 2023 UTC.
* Each stroke were 1 bit, so the numerals would be just a more "compact" representation for binary numbers.
* Even better if they can be represented with a seven-segment display (or other similar displays).
(Though I can't blame them, since these two things didn't even exist back then.)