Re: [TUHS] The 2038 bug...

[Dave Horsfall <dave@horsfall.org>]

On Mon, 4 Jan 2021, Peter Jeremy wrote:

> Alternatively, my understanding is that the Unix epoch changed on 
> several occasions in the early days.  Presumably the knowledge of how to 
> achieve this hasn't been lost.  (Though actually performing an epoch 
> rollover may be more difficult today).

My understanding is that it's been 1st Jan 1970 since at least Ed5, if not 
Ed6.

> I suspect that 2038 may actually wind up being more serious than Y2K 
> because there are now far more embedded systems than there were then but 
> it's not clear that the designers of those systems learnt the lesson 
> from Y2K.  A few weeks ago I tried to count the number of CPUs in my 
> bedroom, bathroom and study - my best guess is around 2 dozen. 
> Admittedly, I think relatively few of those will be concerned about 
> epoch rollover.

The only systems I have that would care would be the various computers, 
and they are all NTP-synced (except the NBN modem/router takes its time 
from T$).

> Plus 2038 is merely one epoch.  Someone mentioned the Microsoft epoch 
> rolling over in 2048.  Between those two, the IBM S/360 epoch rolls over 
> in 2042 - the Z-series appears to have glued another 8 bits onto the MSB 
> end of the TOD clock but that won't help all those S/360 and S/370 
> binaries that are still being run.  And they are just the well- known 
> ones.  I expect that there are lots of embedded systems running custom 
> epochs with weird rollover dates.

Well, I don't care about the M$ epoch, and at 86 I might even get to see 
the world come to a grinding halt :-)  Of course, I may be reliant upon M$ 
systems in hospitals etc...

Interesting story about the S/360 though.  As a side-issue I wonder how 
many COBOL programmers will still be around to maintain all that payroll 
software etc?

-- Dave, who's kept his COBOL knowledge a secret in every job