The following video outlines how to set the timecode from within the BLINK Hub app:
Highlight the master unit and open its Unit Settings using the icon in the bottom right hand corner.
You will be given the option to set the timecode and can choose to either enter the timecode manually, or use the 'Auto and Send' option, to use the local time on your device.
The newly entered timecode will appear at the top of the app, and will be transmitted from the master unit to all receiving slave units.
NB. You will only have the option to set the timecode from the master unit's Unit Settings, as the slave units receive that information from the master transmitting unit.