time_sessionday

The UNIX time, in milliseconds, of the trading day the current bar belongs to. For instruments whose session starts the evening before, it gives the date the session is traded for rather than the calendar date of the bar.

          //@lipi=2
indicator("time_sessionday Example", overlay=true)
newTradingDay = time_sessionday != time_sessionday[1]
bgcolor(newTradingDay ? color.new(color.blue, 0.3) : na)