I'd like to correct my logbook by adding a location for pre a date and post a date. I'd like to not have to update them one by one. Is there a way to change the location for multiple log entries at the same time?
First Backup your logbook.
Select the QSOs from the pre date and post date and highlight them.
Then right click on the selection and select File/Bulk Editor/Any fields.
Click the Fields tab and then "Add Field"
From the Field drop down menu select the field you want to edit.
e.g. it could be the Address or Locator WHY.
If it is a country you can select it from the List drop down.
Click OK and the QSOs will update.
Here's the reference in the online manual that you'll need:
Mike, VK4EIE, WA9PIE