I need to move history from one tag to another. For reasons, I need to remove one tag and replace it with another but I need to keep the history, and it's on about 80-100 tags.

Does anyone have a strategy for migrating data from one tag into another in bulk fashion? Exporting the data, massage the date and timestamp and do the CSV import would take much too long.

Thanks.

That's the only way.

It doesn't take long at all once you develop some automated tools (ex. Python) to do this. You could do 100 GB export of thousands of tags down to 10 GB and import it in a day easily.