[Info-vax] Significance of 2020 / 2021 date

[Hein RMS van den Heuvel]

On Thursday, January 7, 2021 at 12:05:45 PM UTC-5, issinoho wrote:
> We have some old 90s VAX C code which rejects any dates after the year 2020 so, as you can imagine this has now kicked in. The system was ported from VAX to IA64 years ago and we've only just discovered this. 
> 
> Question: is there any inherent architectural or numerical significance behind this, or was this simply 'a date a long time away' when it was coded? 
> 
> Your wisdom, as always, is appreciated. 
> 
> TIA

Cute!

My guess is some application code trying to be 'helpful' thinking it is preventing bad date data entry.
Did it start 2021/1/1 ?
What is the  failing behaviour? 
Some nice error message? System-ish language or native application style message?
 Some 'service failed code xyz' 

I'm not aware of any numbers running out, rolling over, or similar involving 2021
The world in general has not made observations either - 

https://en.wikipedia.org/wiki/Time_formatting_and_storage_bugs#Year_2021

fwiw,
Hein