MarketSession

 using cAlgo.API;
 namespace cAlgo.Robots
 {
     [Robot(AccessRights = AccessRights.FullAccess)]
     public class Test : Robot
     {
         [Parameter("Working Session", DefaultValue = MarketSession.London)]
         public MarketSession WorkingSession {get; set;}
         protected override void OnStart()
         {                       
             Print($"Current Sessions: {MarketSessions}");
         }
         protected override void OnTick()
         {
             if (!MarketSessions.HasFlag(WorkingSession))
                 return;
             // Do something on WorkingSession only
             Print("It's working session");
         }
     }
 }

 import clr
 clr.AddReference("cAlgo.API")
 # Import cAlgo API types
 from cAlgo.API import *
 # Import trading wrapper functions
 from robot_wrapper import *
 class Test():
     def on_start(self):
         print(f"Current Sessions: {api.MarketSessions}")
     def on_tick(self):
         # WorkingSession is a parameter of type MarketSession defined in C# file of cBot
         if api.MarketSessions.HasFlag(api.WorkingSession) == False:
             return
         # Do something on WorkingSession only
         print("It's working session")