It's a pretty old term, to distinguish from e.g. CPU time. This was in common usage even 30 years ago.

Example from 15 years ago: https://stackoverflow.com/questions/7335920/what-specificall...

Trying to make us feel old? Very common term among people around my age and higher (40+). Please don't turn "I've never heard that expression before" into "must be AI saying it".

As old as time.

https://ss64.com/bash/time.html

It's a standard term and has been for ages. It distinguishes end to end time vs eg the amount of CPU time an individual process uses (which excludes time spent waiting for the system or time when the process was otherwise not scheduled on the CPU).

“Wall time” is a pretty common systems term (you see it when comparing total runtime to kernel time, for example). I wouldn’t have indexed on “wall clock time” or other variants as an LLMism.

I've used wall clock for many years, normally when compared to CPU time when talking about parallelizing some process.

CPU time might go up while wall clock time goes down

Wow...it's super common. For example, timing a program you can get user CPU time and then wall clock time, which can be two very different numbers.

Lolwut? You seriously have never heard anyone say this before?