Yes, you can.
- Make you desired Trading Session settings.
- Import your portfolio in the Validator and "Recalculate".
- Export the portfolio. It will have the trading session settings included.
You can also modify the settings within the Portfolio Expert. Be careful that the times are in seconds from midnight.
// Session time is set in seconds from 00:00
const int sessionSundayOpen = 3600; // 01:00
const int sessionSundayClose = 25200; // 07:00
const int sessionMondayThursdayOpen = 3600; // 01:00
const int sessionMondayThursdayClose = 25200; // 07:00
const int sessionFridayOpen = 3600; // 01:00
const int sessionFridayClose = 25200; // 07:00
const bool sessionIgnoreSunday = true;
const bool sessionCloseAtSessionClose = false;
const bool sessionCloseAtFridayClose = false;
Also the trading times is the timezone set to what your timezone is in MT4?
The Trading Session and all times in EA Studio are taken directly from the data file. it means the Time Zone is always the same as the data server.