Logging order status change

Logging order status change

Hello all,

I am using creator to manage all my orders, so each record represents a order and I have an "order status" field.

Order status: 
1. started  
2. stage 1
3. stage 2
4. completed

I want to log the time every time the status changes as well as the changed-to status. Can some one provide some advises?

Ultimately i would like to calculate the time spent in between each phases. thanks!!!!