When i want to query ga:users with dimension ga:date, I get wrong numbers but if i don't use any dimensions, the result is OK. For example, the users number in the date 2018-01-01 to 2018-01-31 return 119 users but when i add ga:date dimension, it returns 133.
I guess users are counted as a sum of lines.
Example
Let's say 1 user entered the site every day during 5 days.
If I request report for a period for 5 days I will have 1 user.
If I split report by days I will have 1 user per day. Total (sum of lines) = 5 users