If you want to exclude weekends from the days added to the date, you can use an expression like this (it currently doesn't work if the selected date on the date picker is on a weekend, but can be adjusted if this is a problem):
With(
{ weekDaysToAdd: Value(Date_Estimator_LBL.Text) },
With(
{
fullWeeks: RoundDown(weekDaysToAdd / 5, 0),
remainingDays: Mod(weekDaysToAdd, 5),
daysToWeekend: 5 - Weekday(DatePicker1.SelectedDate, StartOfWeek.Monday)
},
With(
{ daysToAdd: fullWeeks * 7 + remainingDays + If(remainingDays > daysToWeekend, 2, 0) },
DateAdd(DatePicker1.SelectedDate, daysToAdd))))
Or if you want to get the first weekday after adding the days:
With(
{ dateAfterAdd: DateAdd(DatePicker1.SelectedDate, Value(Date_Estimator_LBL.Text)) },
With(
{ weekday: Weekday(dateAfterAdd, StartOfWeek.Sunday) },
DateAdd(dateAfterAdd, If(weekday = 1 /* Sunday */, 1, weekday = 7 /* Saturday */, 2, 0))))
Hope this helps!