Theben TC 649 E Manual page 21

You need the Theben OBELISK top2/3 software to create an Obelisk file. You
can download the software via this link:
https://www.theben.de/ocsmedia/optimized/full/o4515v48%20OBELISK_top
2_3_V3.8.3.8%20-%20Software.ZIP
Loading ot2 file (switching times) on to device
 Create an ot2 file using the OBELISK software (see above).
 Go to Select ot2 file in the TC 649 E user interface.
 Click on Download ot2 file in order to transfer the ot2 file to the TC 649 E.

The ot2 file download can take a while. The time required for the
download depends on the number of switching times.
5.3.3 Astro offset
The offset for astro switching times can only be set for channels which use the
astro functionality. The astro functionality for the individual channels must be
stored in the OBELISK software.
The astro offset can be changed to values within the range -120 minutes to
+120 minutes.
Changing the astro offset
 Set the desired offset value for the relevant channel using the slider or the
input field.
 Click Save to transfer the offset settings to the TC 649 E.
TC 649 E Manual
Controls and menu
21