For data loggers that connect to a computer using a USB cable or pad, the time and date in a data logger is set at the start of every logging run and is taken from the clock of the PC that the unit is started on.

For Tinytag Connect products (Radio and LAN data loggers) the computer running the Master Connect Gateway sets the time for the system and loggers are automatically adjusted, as required, to keep them accurate.

If the time or date on the computer being used is set incorrectly, recorded data will then show the wrong time or date, so it is important to ensure your PC clock is always set correctly.

The crystal accuracy for Tinytag Talk 2, Ultra 2, Plus 2, View 2 and CO2 data loggers at 25°C is ~20ppm (which equates to a maximum drift of ±1.73s/day).

At other temperatures, the crystal accuracy is as follows:

-10 to +60 deg C: ±50ppm (±4.32s/day)

-30 to +80 deg C: ±130ppm (±11.232s/day)

Data loggers that connect to a computer using a USB cable or pad are not aware of the time zone where they were launched. For example, data from a logger launched at 18:00 in London will show a start time of 18:00 when viewed in New York.

The times displayed by Tinytag Explorer are calculated when the data is displayed and depend on the daylight saving settings of the PC at that time.

For example, if a .ttd file is opened before and after DST settings change, then all times displayed by Tinytag Explorer will go forward or back.

The advantage of this approach is that the relative time information is always correct. For example if a logger is set to record once every 24 hours and is left running during a DST transition all the timestamps will be 24 hours apart.

Unfortunately, this approach means historic data may appear wrong if DST has changed since the data was recorded. For example, a .ttd file from a logger that records every 18:00 GMT in the winter will display 18:00 when viewed in the winter but 19:00 when viewed during the summer.

Please note: describing how the data is displayed by Tinytag Explorer on PC's in countries that apply different DST rules to those where the logger was launched is beyond the scope of this article. Please contact us at [email protected] if you require an explanation of this.