Data sorted when sheet opens

Paste the following macro into the ThisWorkbook tab in the VBA editor (Alt F11) and adjust as necessary to specify the sheet, the range of data and the column to sort by.

Private Sub Workbook_Open()
Sheets("MySheetName").Cells(1, 1).CurrentRegion.Sort Header:=xlYes, key1:=Sheets("MySheetName").Cells(1, 1), order1:=xlAscending
End Sub