I've run into an issue where the Timechart interprets the .time() function differently depending on the zoom level, this is an issue as the chart offsets depending on the previous zoom level when the same timestamps are passed into the .time() function to change the display period.
You can take a look at the issue here, by clicking 'Month' and then 'Day' twice, you will notice that after the zoom level is down to day, it will interpret the same time stamp correctly instead of offsetting the display period by 2 hours.
Also theres an somewhat connected issue with .targetTime() function as it shows different times depending on the zoom level as well. At the top levels it shows 02:00 as the time but as soon as I'm down in the day it's correct at 00:00.
Would like a fix for this inconsistency.
http://jsfiddle.net/v5hsn17k/2/
Cheers.