Help with automation sun

Configuration
1

Hi all,
i need an automation condition that give me true if the actual time is 2 hour befor sunset to continue the automation only if there are more than 2 hour left to the sunset…

I thinked to do something like this:

if ( (actual time + 2 hour) < sunset time )

but i’m not able to work on math with time and timestamps

can anyone help me?
thanks

2 
- condition: sun
  before: sunset
  before_offset: -02:00:00