cron

there is the following example:
// runs./jobs/worker-8.jsat midnight (once) { name: 'worker-8', timeout: 'at 12:00 am' },

in my usecase i am running a job every 30 minutes that queries an api and dynamically adds jobs to be executed once.
My question is what happenes to the jobs in the queue after they are executed. Will finished jobs be cleared out automat

I need something like below:

newCronExpression = convert (localCronExpresn,fromLocalTZ, "UTC")

Is it possible using cron-utils?

Let me give an example:

My local timezone is IST i.e. GMT+5.30.

Current local time is: 11:20 AM.

I want a job to run in 45 min of every hour.

So, my cron expression: 45 * * * *

Hence I am expecting my job to run after 25 min ( as starting time