In that direction on the sleeper? The problem is that Springburn-Ashfield has no direct trains other then the sleeper. The same applies for the other direction (Ashfield-Bishopbriggs). An approximation given below. Allow about a mile in each direction for the missing gap, but I can't give you an exact value I'm afraid
NORTHBOUND=51 miles, 42 chains
Edinburgh-Springburn=47 miles, 54 chains
Ashfield-Westerton=3 miles, 68 chains
SOUTHBOUND=47 miles, 70 chains
Westerton-Ashfield=3 miles, 68 chains
Bishopbriggs-Edinburgh=44 miles, 2 chains
As mentioned above, this will depend on the routeing your train took.