Create custom date range with same start date and different end date

[anam0904]

How do I create a custom date range that has the same start date but different end date? I want the start date to always be on Sunday, but the end date to be the current date. Ex: On Wednesday, I want to send myself a look with a date range from the previous Sun-Wed, and on Thursday (from Sun-Thurs) and Friday (from Sun-Friday), and so on. Essentially, it’s a cumulative look. Is this possible to do?

[Dawid]

Where do you want to create this range? What dictates the range? Is it not achievable with simple filters? It looks to me like you’re looking for a WTD calculation, In this case you can use Looker filter on datetime dimension called  Last 1 week. This only looks at current week. 

In LookML you can set up what is your starting day of the week in the model file

week_start_day: sunday

https://docs.looker.com/reference/model-params/week_start_day