Line graph with start and end date

Hi guys,

I know this is a widely discussed problem, and there are many solutions around on the PowerBI forums but I can't get any of them working for me somehow. Could anyone help me out?

I have a table of units, when they entered the warehouse and when they left the warehouse, like so:

I also have a date table with date, month, year, quarter, etc.

Now I want a line graph to show for every date how many units were in the warehouse for that date.

I tried the following solution, but it returns a very high number of units on any given date and I can't figure out why. It seems to work fine for the linked case and mine is basically identical.

https://community.powerbi.com/t5/Desktop/Make-line-graph-with-starting-date-and-end-date/m-p/804322#M386864

UNIT Count = 
VAR _FirstDate = FIRSTDATE ( Dates[Date] )
VAR _LastDate = LASTDATE ( Dates[Date] )

RETURN
CALCULATE (
    DISTINCTCOUNT ( Table[UNIT] ),
    Table[DateIn] <= _LastDate,
    Table[DateOut] > _FirstDate || ISBLANK ( Table[DateOut] )
)

Please help!