Hi all, I have a problem creating a time chart based on calculations of 2 values from different source-type. Let me put this below: Source type A: It stores all customers in certain service, and each of the customer will be given an unique indicator call bsn. Each of the entry was given with a same _time, i.e. 2020-08-01 00:00. The # of rows could represent # of customer in August, say it is num2. Source type B: It stores all the maintenance order received from the pool of customers in source-type A. In general, i will need to count # of customer in specific requirement (which say he is male) has put an order in august. For this number, it is num1   So the idea is want to create a time chart, to show the order rate (num1/num2) by each month accordingly.  However as it involves different source type, while their _time is quite different from one another. I got problem on solving this. Please help ... View more