Why Do Your Arrival Times Have Two Times?

We used to tell customers that we would arrive at (say) 8 a.m. At 2 minutes past 8 a.m. many customers rang, concerned that we may not arrive (we have NEVER failed to do a job). We will not promise anything we can not deliver.

We give you two times, between which we estimate we will arrive. 87% of the time we arrive near the first time but we cannot estimate the exact time the previous job will end.