By default, weekends are defined as non-work days. So if you choose a weekend date, FastTrack Schedule will automatically select the next available work day. You will need to modify the work calendar to allow activities to be scheduled on weekend days.
To access work calendar settings:
1. Go to Project > Work Calendars
2. If you want to activate a specific date, select any weekday with an 8-hour work schedule
3. Select 'Copy Day'
4. Select the desired weekend date
5. Select 'Paste Day'
6. If you want to activate all Saturdays/Sundays in the calendar, select 'Sat'/'Sun' under 'Define Typical Week Day'