[visualization-api] Why date values are repeated on horizontal axis in Webkit browsers?

2014-10-03 Thread Василий Топоров
Hello. I've got a problem with Line Chart. On this page http://www.metrtv.ru/price_dynamics we have charts of changing price on real estate (hAxis - date, vAxis - price). This values are taken by jquery ajax from pre-generated json files (one file for one chart). On windows machines in

Re: [visualization-api] Why date values are repeated on horizontal axis in Webkit browsers?

2014-10-03 Thread 'Sergey Grabkovsky' via Google Visualization API
Hi Vasiliy, This appears to be due to an issue with time zones and certain operating systems. I was able to reproduce your issue on Windows 8.1, but not Windows 7. Could you please elaborate on which version of windows you're running? On Fri Oct 03 2014 at 9:30:44 AM Василий Топоров

Re: [visualization-api] Why date values are repeated on horizontal axis in Webkit browsers?

2014-10-03 Thread 'Sergey Grabkovsky' via Google Visualization API
Hi again, I looked into this, and as I thought, it's because of Daylight Savings Time. Apparently, until the end of 2013, Russia was using permanent Daylight Savings Time (reference http://en.wikipedia.org/wiki/Daylight_saving_time_by_country). In 2014, they returned to Standard Time. As a

Re: [visualization-api] Why date values are repeated on horizontal axis in Webkit browsers?

2014-10-03 Thread 'Daniel LaLiberte' via Google Visualization API
I wonder about the UTCYear solution, though. What will it show when UTC has crossed the year boundary but the local date has not? I think the whole thing about showing local dates and times is wrong. The data should specify the location where a date applies, and we shouldn't assume the local

Re: [visualization-api] Why date values are repeated on horizontal axis in Webkit browsers?

2014-10-03 Thread 'Sergey Grabkovsky' via Google Visualization API
That last part is basically what the solution is. It's to calculate the ticks using UTC time, so we don't get into weird situations with DST, but still display local time. UTC is smarter, so when you do Date(2013, 0, 1, 0, 0, 0) + 1 year, it will be Date(2014, 0, 1, 1, 0, 0); where if you did that