The timer will always execute a job once, even if it is after the scheduled endtime for the job.
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2026.08.27D12:27:31.362795220
.timer.rep[2026.08.27D08:00; 2026.08.27D10:00; 0D00:00:05; ({.lg.o[`timerjob; "Run a job"]}; `); 2h; "Run a job"; 0b] // endtime is in the past
q)2026.08.27D11:27:40.192254803|homer.aquaq.co.uk|test|test|INF|timerjob|Run a job
...
The timer will always execute a job once, even if it is after the scheduled endtime for the job.