May 17, 2019
My smart thermostat (Toon) allows me to download info re electricity and gas usage, thermostaat settings and lots more on an hourly and for some things on a 5 min basis. PQ is just great to process this but I'm having a problem with adjusting the data to correspond with Daylight Saving Time (DST) time changes.
So lets assume I have a year's worth of data per hour and on March 29 at midnight we set the clocks forward, then on October 25 set them back an hour again. So in my date/time column I need to make the appropriate adjustments. Setting clocks forwards means inserting an hour with no data? or is the day just shorter - I think so. Setting back needs to combine two hours to one or should the day be 25 hours? Cant quite get my head around how to implement this. I''m sure I'm not the only person to have this problem! Suggestions appreciated!
And posting this I see Tomorrow's date while in my country I'm still in today. Doesn't that fit perfectly with my problem 🙂
July 16, 2010
I'd be inclined to ignore the DST time changes because trying to handle them only introduces more issues that are worse in my opinion. If you're looking at data at an hourly level then you'll see the trend change for that first week, but then it should regulate, and vice versa at the other end of DST.
May 17, 2019
Thanks Mynda, yes I've come to the conclusion it isn't worth the effort. However I think the solution is to build a static database and add to that each time I download via PQ. Then its relatively simple to make the DST corrections manually 2x per year. It just irritates me so much that although I know my car is set to charge at 12 midnight the charts show it doing that at 11 pm!