The reason you can't simply turn on Saturday or Sunday is because you already have schedule items on your schedule for that specific job.
We disallow this action because it would adversely effect the preexisting schedule and any linked items. When they were created, it was calculating off a five-day work week versus six or seven.
As a best practice, you should always set your work week before creating schedule items.
Please follow these steps to adjust your work days:
First, you'll need to copy your current schedule to a template. To complete this action, you'll want to click into your job details for the specific job you want to fix:
Next click Copy to Template.
Then, name your template something you'll remember and Click Convert to Template.
Now, return to the Schedule.
Be sure to remember the start date of the first item on your schedule. Now select Delete All Items from the More Actions drop down.
Once you've deleted all the items, you'll now have the option within your Job Details to add Saturday and Sunday as a work day:
After you've set the appropriate work days, return to the Schedule and import the schedule from template.
Next, be sure to choose the correct template and enter the start date you recorded earlier prior to deletion to ensure your schedule returns to its original state. It should now include the added workdays.
You'll now see your schedule back in place, but with weekends available as work days. Remember, adding weekends to the entire schedule will shorten the entire duration of your schedule. If you had linked items such as To Do's or Bids, these items will no longer be linked to your schedule.