Coordinated Universal Time (UTC) is the global time standard. Timezones across the globe (such as the USA’s Easter, Central, Mountain, and Pacific) reference their time off of UTC. For example, Easter Time in the US is either UTC -5:00 or UTC -4:00 depending on daylight savings.
The X2 data logger utilizes UTC time internally in order to mitigate the issues associated with time zones and daylight savings. The internal timestamp for all recorded data is made using UTC time regardless of where the device is deployed or the current status of daylight savings. By using UTC time, the X2 logger avoids issues with adding and losing an hour during the daylight savings transition while also reducing location specific setup requirements.
UTC timestamps can be easily converted to the corresponding local time using the known UTC offset value. WQData LIVE handles this conversion automatically when displaying data based on the user’s profile time zone selection. WQData LIVE also handles calculating the corresponding UTC time when a user enters a logging start time on the website. From a user’s perspective, when interfacing with WQData LIVE, there is no need to even know the device is operating using UTC time.
Also, note that the Greenwich Mean Time (GMT) timezone uses UTC time, so these are sometimes used interchangeably.