as soon as

1. At the earliest moment that, as in Telephone me as soon as you can . It often takes the form as soon as possible , meaning at the earliest possible moment, as in He'll finish the work as soon as possible . This expression employs possible in the sense of “if it can or could be,” a usage dating from the late 1600s.

2. When, just after, as in Please call me as soon as dinner is ready , or As soon as the sun goes down, the temperature drops dramatically . [Late 1200s]