This works for things in the past but not things in the future.
If I say I want something to happen at 8pm New York City time on January 7, 2028 and then the DST rules for NYC change, I likely still want it to happen at 8pm. Converting to UTC and back to local time loses that information and it will happen at the wrong time.
I 100% agree with you, and don't set cron jobs/scheduled tasks this way. I only use this for displaying date/time to users.
With that said, I do appreciate the comment, and would have to make sure that if I run scheduled tasks in the future, they are run when the user wishes them to be completed based on when that user sets it to be completed (so would most likely not convert to UTC, and save the timezone with the date/time).
If I say I want something to happen at 8pm New York City time on January 7, 2028 and then the DST rules for NYC change, I likely still want it to happen at 8pm. Converting to UTC and back to local time loses that information and it will happen at the wrong time.