I'm trying to back fill my summary index one day at a time because my current savesearch contains a lot of regular expressions and can only run 24 hours of data for it not to be truncated.
For example my data if from 01/01/2018 up to present.
So what I want is when i execute the script it will run for 01/01/2018 data. then after it finishes then will run again for 01/02/2018 data until I reach the date yesterday.
Your question makes no sense. Create a different populating search that will run every day for
Last 24 hours and then run the backfill script over as many days as you like. It will run 1 day at a time, over and over.
And that is exactly what I told you how to do. Create a SI-populating search that covers
Last 24 hours or
Yesterday and the do backfill as described here, with the python script: