Get Start and End Date from a Given Date Range

Question

I need to save to a table the fields "startDate", "endDate", and "dateAlias" from a given date range. Saving should be by 30 days. So, let's say the date ranges from January 20, 2020 to march 20, 2021. I need to save to my table a period before the start date starts to the date end like this:

startDate	endDate	dateAlias
2000/01/01	2020/01/19	Month00
2020/01/20	2020/02/19	Month01
2020/02/20	2020/03/19	Month02
2020/03/20	2020/04/19	Month03

and so on.

the start date of the first row is static. I hope someone can help me. Thanks in advance.