Thanks, that makes sense. I just checked the database again and the data are there so I must have been looking in the wrong place, doh!
When it comes to the clocks going back again in October is the same thing likely to happen again? If so I guess the same fix will work again, or is there something I should do to prevent it? On Monday, 29 March 2021 at 00:56:09 UTC+1 [email protected] wrote: > 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/fd1117b9-615a-45dd-8da1-02531ff73ec6n%40googlegroups.com.
