how to achieve 08:25am while typing in grid?

 . Allow user input in the form of hours.minutes. So the user enters 1.25 for 1 hour and 15 minutes.

 

i have a gridcontrol in my project ,in my grid i have a column like time.(00:00)

while typing a time in time column ,im selected  first 00 before(:) colon and im typing 08 ok after that im typing 35 automaticaly it will set in another 00,

how can i achieve this

time

00:00

 my output is 

time

08:35

the colon(:)remains same the time automaticaly  set in hours and minutes column