I inquired with Leviton as to the accuracy of the VTP24 24 Hour Programmable Timer with DST. https://www.leviton.com/en/products/vpt24-1pz Don Resor Here is the reply I received: Hello, Thank you for contacting Leviton technical support. According to the code it meets, it is required to have time keeping accuracy within 5 minutes every year. It also uses a crystal to keep time, as it must maintain the time even during power outages. Regards, Virgilio Dominguez Technical Services Representative II Leviton Manufacturing Co., Inc. 201 North Service Road., Melville, NY 11747

If my watch were that bad, I'd toss it out and go shopping for a new one. I wonder if Leviton offers a version with an external ref input. Dana On Fri, Aug 27, 2021 at 12:12 AM D. Resor <organlists1@sonic.net> wrote: > I inquired with Leviton as to the accuracy of the VTP24 24 Hour > Programmable > Timer with DST. > > https://www.leviton.com/en/products/vpt24-1pz > > Don Resor > > Here is the reply I received: > > Hello, > > Thank you for contacting Leviton technical support. According to the code > it > meets, it is required to have time keeping accuracy within 5 minutes every > year. > > It also uses a crystal to keep time, as it must maintain the time even > during power outages. > > Regards, > > Virgilio Dominguez > Technical Services Representative II > Leviton Manufacturing Co., Inc. > 201 North Service Road., Melville, NY 11747 > > _______________________________________________ > time-nuts mailing list -- time-nuts@lists.febo.com -- To unsubscribe send > an email to time-nuts-leave@lists.febo.com > To unsubscribe, go to and follow the instructions there. >

On 8/27/21 3:30 AM, Dana Whitlow wrote: > If my watch were that bad, I'd toss it out and go shopping for a new one. > I wonder if Leviton offers a version with an external ref input. > > Dana When your requirement is "turn the lights on and off with the sun" 5 min/year is pretty good. OTOH, Perhaps there's an aftermarket for a modified version. Maybe you've got a niche business opportunity there, Dana. "Now, with improved accuracy! Ovenized for better performance! 30 millsecond error in one year! " You might need to gradually change the frequency you feed it, though, because I'll bet their sunrise/sunset algorithm doesn't implement the equation of time. But if you're doing milliseconds, you'll need it. > > > On Fri, Aug 27, 2021 at 12:12 AM D. Resor <organlists1@sonic.net> wrote: > >> I inquired with Leviton as to the accuracy of the VTP24 24 Hour >> Programmable >> Timer with DST. >> >> https://www.leviton.com/en/products/vpt24-1pz >> >> Don Resor >> >> Here is the reply I received: >> >> Hello, >> >> Thank you for contacting Leviton technical support. According to the code >> it >> meets, it is required to have time keeping accuracy within 5 minutes every >> year. >> >> It also uses a crystal to keep time, as it must maintain the time even >> during power outages. >> >> Regards, >> >> Virgilio Dominguez >> Technical Services Representative II >> Leviton Manufacturing Co., Inc. >> 201 North Service Road., Melville, NY 11747 >> >> _______________________________________________ >> time-nuts mailing list -- time-nuts@lists.febo.com -- To unsubscribe send >> an email to time-nuts-leave@lists.febo.com >> To unsubscribe, go to and follow the instructions there. >> > _______________________________________________ > time-nuts mailing list -- time-nuts@lists.febo.com -- To unsubscribe send an email to time-nuts-leave@lists.febo.com > To unsubscribe, go to and follow the instructions there. >

On Fri, Aug 27, 2021 at 9:29 AM Lux, Jim <jim@luxfamily.com> wrote: > > When your requirement is "turn the lights on and off with the sun" 5 > min/year is pretty good. > > When I bought my current house, I forgot to call the electric company before closing, and they turned off the power right at 5am of the day I moved in. I called them that very day, but since it was the Friday of a holiday weekend, they said they couldn't send someone out to get it turned back on until Tuesday, so we had a nice time in the house without power. On Tuesday, right exactly at 5:00, the power came back on. And the old mechanical timer that turned the driveway light on around sunset and back off in the morning didn't need to be adjusted at all — it had missed exactly 96 hours, and came back to life without noticing the difference. Andrew