On Sun, Mar 28, 2021 at 2:36 PM Jon B <[email protected]> wrote: > Ah, thanks, that's done the trick! The data from when the clock changed > now appear on my page. Out of interest - while the logs show that the > records were added to the database file, I've just had a look and there > seems to be a gap from the clock change until I just got it going again, so > where is the data coming from/where has it been added? Also, there's no > hour gap on the graphs for my station, which I thought there would be > (there's data every minute between 01:00 and 02:00)? >
WeeWX uses time.mktime() <https://docs.python.org/3/library/time.html#time.mktime> to convert from local time to UTC. This function takes a "time tuple", one of whose fields is tm_isdst. You're supposed to fill this field out with whether DST is active or not but, of course, we don't know because the Vantage won't tell us. So, we use "-1" which indicates that the system should figure it out. Usually it gets the right answer. Here's what it looks like during the DST transition 14-Mar-2021 here in the USA: >>> from time import mktime >>> mktime((2021,3,14,1,0,0,0,0,-1)) 1615712400.0 >>> mktime((2021,3,14,2,0,0,0,0,-1)) 1615716000.0 >>> mktime((2021,3,14,3,0,0,0,0,-1)) 1615716000.0 >>> mktime((2021,3,14,3,1,0,0,0,-1)) 1615716060.0 You can see that both 0200 and 0300 give UTC time 261571600. No gap. You didn't say how large a gap there was in your database. There shouldn't be one because, although local time is discontinuous, as we have seen, UTC is not. Perhaps the logger lost a record when it became corrupted? This is also why there is no hour gap in the plots --- time didn't stop or jump ahead, it just changed how it was labelled.. Indeed, if you look closely, you'll see that the vertical tick marks between midnight and 3am are a little closer together than they are between 3 and 6. Hope this helps. -tk -- You received this message because you are subscribed to the Google Groups "weewx-user" group. To unsubscribe from this group and stop receiving emails from it, send an email to [email protected]. To view this discussion on the web visit https://groups.google.com/d/msgid/weewx-user/CAPq0zEBdOpD82WYgkFGm3eh7QcZDD0pC%3DfVp5xfGJBTGhe0NNw%40mail.gmail.com.
