Filter Calendar lookup table based on fact table value

[NegaStar]

Hi All,
I would like to ask your help to find a solution of the following case.
I would like to get the minimum Calandar[Date] value which is equal or greater than TransctionPast[FirstValid] date.
Here are the relationships:

I created the following measure but it just uses a lot of RAM without any result, when I tried to put it in it in a power pivot's value section

I think it is caused by the relationship and the filter direction but I can not figure out how to get the required date value.
I would use it for further calcualtion which will be in the value section of a power pivot.
Could you help me to define the required measure? Please see the sample file on the following link. Thank you very much in advance!
Power Pivot Sample

 

[RET]

Not fully sure, but try:

VAR MinFirstValid = MIN(TransctionPast[FirstValid])
RETURN
CALCULATE(MIN(Calendar[Date];
FILTER(Calendar;Calendar[Date]>MinFirstValid)
)