[Timezone] Heatmap dates getting duplicated between end of previous week and start of next week

[kimili]

Expected Behaviour

The heat map date calculation should not duplicate dates.

Actual Behaviour

The last day of a week in the heat map is getting doubled as the first. Note that this also has the effect of incorrectly rendering the last day of a month and the first day of the next month, so the months do not stack correctly.

Steps to Reproduce:

• Simply render the demo and examine the dates on the end of one week and the beginning of the next week.

Some examples:

May 7, 2016

October 1, 2016

Frappé Charts version: 1.1.0

I'll look into it and see if I can figure out whats going on and open a pull request if I can patch it.

[pratu16x7]

Browser?

On Chrome:

[kimili]

@pratu16x7 - It's very strange that you're seeing it correctly and I am not. I noticed the problem initially in Safari (11.0.3), but I checked in the latest versions of Chrome, Firefox, and Opera - all on MacOS 10.13.3. I'm seeing it constantly incorrect in all those browsers.

Can you double check https://frappe.github.io/charts/ in different browsers, or in an incognito window to eliminate the possibility of caching issues?

[kimili]

You can see there's something going wrong - at least on my end - in the startOfWeek calculation. This is a log out of each week's data in the getDomainConfig() method. All the startOfWeek values should be on a Sunday:

[kimili]

@pratu16x7 - OK, it looks to be a timezone - and time of day - specific problem. When I set my clock to GMT, it works as expected. However, when I seeing to my local timezone - Eastern Standard Time - that's when the issue surfaces.

I think how days are being calculated to render the grid isn’t taking into account time zone offsets and perhaps daylight savings time, so the day additions get thrown off.

I'll continue digging and look for a fix.

[Neo-Desktop]

Just to bump this up, this behavior is still present and I feel like it's related to #318