Say
`SELECT julianday('2021-01-02 01:00:00')-julianday('2021-01-01 04:00:00')
`
1 day and 3 hours will be 1.125 days
= 2459216.5416666665 - 2459215.6666666665 = 0.875 = julianday
How to transfer this 'julianday' back to **days**?
For example, 10 days and 6 hours will be 10.25 days
EDIT: Better explanation