not completly, with salary it is calculated based an average of whatever they use for it, generally it is the 5 days a week at 8 hours a day 52 weeks a year. Additionally upon entering the job you are given your expected hours and weekly workload, and that is how you judge if the pay is worth it. Signing up for a job saying they are going to work you 8 hours a day 5 days a week and they're going to pay you 40,000 for it, that is about 19/h

However if you agree to that wage and then you find out that you're expected workload is actually 10 hours a day for 5 days a week that brings your estimated hourly wage down to 15/h, a wage that you might not have accepted if they were honest right up front with it.

On top of that, not all salary positions are considered exempt positions, surprisingly few are when you look at the requirements, so if you agreed for that position face off the average work week of 8 hours a day 5 days a week, and you start averaging higher than that but they don't change your salary to match it, if your position is not considered exempt you are still obligated for overtime.

Of course this is based off the US not sure how the rest of the world is