Gallery Filter to display items not modified within timeframe

[Doors1980]

I have a standard formula filtering my galley but need to modify it to include only items that have not been modified in the last 14 days.

SortByColumns(Filter(Search(Issues, "Active", "Status"),(TextSearchBox1_3.Text in Issue)), "Modified", If(SortDescending3, Ascending, Descending))

Any help would be greatly appreciated! 

[CarlosFigueira]

You can use the DateAdd function to compare against the Modified column in your data source, something along the lines of the expression below:

SortByColumns(
    Filter(
        Search(Issues, "Active", "Status"),
        TextSearchBox1_3.Text in Issue,
        Modified < DateAdd(Today(), -14, Days)),
    "Modified",
    If(SortDescending3, Ascending, Descending))

[Doors1980]

Thanks for the reply @CarlosFigueira 

Two issues though:

1. The formula you have suggested does not return any results for the Gallery and has the yellow errors.

However a simplified version does work and the gallery populates:

Filter(Issues,Modified > DateAdd(Today(),-14,Days))

2. Your suggested formula returns items that have been modified in the last 14 days, I need the opposite - Items that have not been modified in the last 14.

Cheers.