i hope someone out there can help me or point me in the right diection. i am quite new to Excel so please forgive me for sounding dumb (still learning) i need to know how to complete a time arrival sheet. example-

A B C D
Vehilcle. due at. arrived at. minutes late.
A Lorry 18:00 18:25 25
A Car 19:00 19:15 ??

I would like to acheive that column D shows minutes late/early after inputting arrival time, Also, can colum C show the time of arrival at the present time and not be changed once the arrival time has been entered. i hope someone out there can help me this will make things at work so simple. Many thanks

segger