FLOOR Rounds a number down, toward zero, to the nearest multiple of significance.
Syntax
FLOOR(number, significance)
Parameters
Number – The numeric value you want to round.
Significance – The multiple to which you want to round. The argumentsnumber and significance must either both be positive, or both be negative.
Return Value
A decimal number.
Reference Data
https://docs.microsoft.com/en-us/dax/dax-function-reference