A standard intervalometer usually only repeats at a fixed interval, so for irregular times you have two practical low-cost options:

1. Shoot at the smallest common interval and keep only the frames you need. In your example, a 30-minute interval covers all the listed times. This is the simplest setup, but you’ll create extra images to discard.

2. Use a simple microcontroller trigger. An Arduino can trigger a compatible camera (one answer specifically mentions Canon) at exact programmed times. That gives you the specific schedule you want without extra shots. According to the community answer, this can be done inexpensively and calibrated well enough to keep time, with an occasional reset if needed.

If minimizing hassle matters most, use the intervalometer approach. If minimizing unwanted images matters most, a small programmable trigger is the better fit.