Sorry for missing this earlier,

Not really sure without trying it myself. You want the net result of that to be a string formula that excel will interpret correctly.

Apparently excel interprets "1/1/1970" as =

**25569**. So replace your magic string with that. The -5/24 represents the timezone offset, if you log locally (your data is where you are) then you can eliminate that.

So your formula would be:

ts / (1000*60*60*24)+25569

Another thing is you are not logging this to the dbLog, instead this is done

on this line in index.html:

`dataString = logItem.t + ',' + logItem.v;`

So to add a new column with the excel date, modify it to this:

`dataString = logItem.t + ',' + (logItem.t/(1000*60*60*24)+25569) + ',' + logItem.v;`

Try that, let me know what you get...