The HOBO RX3000 knows nothing of Standard Time (ST) or Daylight Saving Time (DST). Data is always logged at UTC (Coordinated Universal Time) and the appropriate offset is calculated per your settings in HOBOlink.
In the Time Zone field, select the time zone where the device is located. This setting ensures that the time-stamp associated with each logged data point is displayed properly for your region. If the time switches between DST and ST during logging, the time shown on the graphs on your device page will be adjusted automatically.
If your exported data includes the transistion between ST and DST, the proper time offset is applied by HOBOlink when the export is generated.