TimeZones and backtesting

I'm having trouble finding a definitive answer and was hoping someone could clarify for me. If I have a robot set to Eastern Standard Time and use code that targets specific EST windows, when using the backtester will it automatically handle daylight savings time for the historical dates or does it use the current (today's) UTC offset?  For example, we are currently in DST so the UTC offset for EST is -4. But if the backtester is running bars from February of this year, an offset of -5 should be used.

Thanks!