Since most people work their schedule around standard business days (Monday-Friday), tasks reminders have been modified to work how you do.
When setting up Tasks to send you a reminder ahead of the Due Date, you can enter the number of days prior to the Due Date that you want that reminder to be set. Weekends will no longer count when considering the number of days.
In this example, the Task is due January 30, 2017 - a Monday. This task is set to send a reminder 1 day prior. Instead of reminding you on Sunday, when you are not at work, it will remind you on Friday.