[HECnet] How long has your 20 been up?

[Johnny Billquist]

On 2022-01-19 01:57, Paul Koning wrote:
> 
> 
>> On Jan 18, 2022, at 7:48 PM, Johnny Billquist <bqt at softjar.se> wrote:
>>
>> By then, we probably also need to look at/revise how we compute leap years... It's well known that the current algorithm will slowly get us out of phase again...
> 
> The Gregorian algorithm is amazingly accurate, I wonder if the earth rotation slowing down is the bigger issue.  Then again, I suspect a whole lot of computer date algorithms will get 2100 wrong; I know RSTS has the Julian leap year rule.  Not that it really matters given the Y2035 issue...

It is fairly good, but not perfect. I think it have been brought up that 
there should be a 3200 year rule, beyond the 100 and 400 rule. The 
Wikipedia article says it should be a 4000 year rule 
(https://en.wikipedia.org/wiki/Gregorian_calendar#Accuracy). So either 
I'm misremembering, or else there are some different ideas about this...

RSX will deal correctly with the 4/100/400 rules (which means we're 
talking Gregorian). I think pretty much everything in RSX is secured up 
until 2155, and before then I think the only problem is DECnet, and 
things like FLX which deals with RT-11 filesystems.
Beyond 2155, a few more things will cause problems, but nothing 
catastrophic.

   Johnny

-- 
Johnny Billquist                  || "I'm on a bus
                                   ||  on a psychedelic trip
email: bqt at softjar.se             ||  Reading murder books
pdp is alive!                     ||  tryin' to stay hip" - B. Idol