[Info-vax] clock problems with OpenVMS x86 on VirtualBox

[Dan Cross]

In article <024ad569-cc96-4908-be2d-55f6f7b1ac6an at googlegroups.com>,
David Jones  <osuvman50 at gmail.com> wrote:
>On Monday, May 15, 2023 at 4:37:47 PM UTC-4, Dan Cross wrote:
>> In fairness to your laptop, it probably has a very good clock. 
>> Drift of the kind discussed in this thread would take place over 
>> days or weeks, not just hours. 
>
>For connecting to my Raspberry Pi's, I bought a cheap PCF8523 RTC
>($7) and a better DS3231 RTC ($25), the better one being accurate to
>3 seconds per month. A drift of 100ms per day can be detected over
>12-18 hours or less. What incentive do they have to put a super
>accurate clock in a computer they expect to be on the network and
>talking to time servers?

It would be interesting to stop any NNTP service you may be
running (e.g., on a host) and see if you observe that.

>Why did I buy an RTC for my Pi? I'm doing data collection with it and
>Pi's don't have an RTC on the card. If it boots after a power outage,
>there is a window where timestamps will be wrong because it starts
>the system time at the last checkpoint and runs with that until it can
>get a correct time from either an NTP source or an external clock. I
>have a cron job that syncs the RTC with an NTP source every 10
>days.

Nifty.

	- Dan C.