Variable Start and End Time per Country

Not sure if I understood your problem statement correctly on how dynamic you want this to be , but as a generic - 

1. Create two custom columns 1 for start time and 1 for end time

2. sample dax for start -

Business Hours Start =

var _bushourstart1 = Time(09,45,00)

var _bushourstart2 = Time(11,45,00)

Retrun 

switch(

True(),

table[country] == "USA", _bushourstart2,

table[country] == "UK", _bushourstart2,

table[country] == "France", _bushourstart1,

table[country] == "Greece", _bushourstart2

)

3. do the same step for endtime

if you want dymamic then need to put these country and start and endtime in a master table or file then join with data table and need to change the dax field accordingly