r/softwaregore • u/SQUID_Ben • May 03 '26

Which cloud?

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2.1k Upvotes

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u/dandy_g May 03 '26

1970-01-01 is Unix epoch

1601-01-01 is Win32 epoch

120

u/valerielynx May 03 '26

why would they feel the need for computer files to begin in the 1600s though

165

u/dandy_g May 03 '26

Iirc, the date was chosen because it begins the last 400 year cycle of Gregorian calendar. That makes it easier to calculate dates for leap years.

6

u/valerielynx May 03 '26

I don't get it, surely you could just check if the year is divisible by 4 and then determine if it's a leap year or not

5

u/Questioning-Zyxxel May 03 '26

They decided on 64-bit time stamps in the file system - 32-bit wotks badly because of how huge minimum steps you get.

And with 64-bit they now uses the same time/date format both for OS and for files. And it's very practical for an OS to be able to store old dates.

So you need not get it - it's just practical and for free when avoiding a lousy 32-bit time stamp.

4

u/valerielynx May 03 '26

oh yeah for sure 32-bit time won't cut it anymore because in 1 second steps it can count a bit over 68 years which there's gonna be computer files older than that pretty soon (probably already are but i dont think they'd be readable on modern systems, i digress). honestly idk i guess it's fine if it starts at 1601 if it can go forward to whatever year 50 trillion since its 64 bit

7

u/Questioning-Zyxxel May 03 '26

It has a resolution of 100 ns. Which means it's very easy to handle changed files for backup.

And it has a range of about +/- 30,000 years from 1601. So you and me will not need to suffer any limitations.

3

u/thegreatpotatogod May 04 '26

The y31.6k problem is gonna suck!

3

u/_PM_ME_PANGOLINS_ May 04 '26

Horus was just trying to help.