Looker Aggregate Awareness requires the date filter to be exactly the same, which is weird

[vuyoung191]

I have a table with a daily metric, and now I want to add aggregate awareness to have weekly metrics handy. Below is my codes:

    query: {
      dimensions: [date_week]
      measures: [number_of_subscribers, number_of_unsubscribes]
      filters: [
        postscript_daily_agg.country_filter: "United States",
        postscript_daily_agg.date_date: "1800 days"
      ]
    }

 Now when I explore the table and have a date_date filter of 60 days, it doesn't use the aggregate table, and I feel that's nonsense. It says 

-- Did not use postscript_daily_agg::rollup__date_week; contained filters not in the query: postscript_daily_agg.date_date

I tried removing the date_date filter in the aggregate block, and it didn't work either. I only works if I put the exact date_date filter of 60 days. What did I miss?