How can I stick to a specific bedtime/waketime when I work weird hours?

It will be hard! You may want to schedule specific nap-times as well so if you are available to take a nap, you can at least salvage some of that missed sleep, and scheduled nap-times will help keep your sleeping schedule consistent. Remember, it is okay to go to your boss and say, "I cannot work from X to X, but I am willing to work any other hours." If your boss doesn't go for it, at least you know you tried, and you have an opportunity to look for a job that will be more accommodating to your health.

When I worked weird hours last summer, I found myself sleeping only 3 or 4 hours some nights. I decided to make a chart to log which nights I could get more regular sleep and it was much easier to have a visual to work with. I was able to plan better and even schedule time for naps to keep me refreshed on days I had to work nights. This worked for meal planning as well, which is also important to maintaining energy.

Try to manage my time better. Keep on being straight with the schedule and doing exercises will help to have a good quality rest.

You can stick to a specific bedtime/wake time when you work weird hours by setting an alarm for every morning, and sticking to it. If your work hours change often, it may be impossible to achieve this goal. The same goes for a specific bedtime.

There are 2 broadly suggested tricks for that: 1. Have a dark and comfortable place to sleep, our brain understands those feelings as triggers to go to sleep; 2. Develop rutine and tricks that trigger the process of going/waking up of/from bed, something that you do every time before and after bed (in my case I read before sleep and I brush my teeth as soon as I put one foot out of bed), but avoid screens and similar devices at least 30 min before going to sleep