Working overtime is definitely not an issue depending on how frequent or consistent it is actually. Working overtime on a short time duration is normal probably due to more workload or more clients demands then it is perfectly understood and normal.
For example a banking hall where sometimes they get too many customers even after closing hours, it is not bad if you work over time in this kind of situation since it is a rare period at the office but once it begins to turn to a long time overtime work then certainly there would be issues eventually especially if it isn’t even yielding a promotion or a salary raise then it is definitely not fair on your part. I think it might be time to actually re-evaluate and re-strategize your plans.
To re-strategize you have to look into how often you really do work overtime and also consider the amount of your time it actually consumes on your end too.
Take into consideration times you have to resume earlier than stipulated time, close later than stipulated time, times you have to miss your lunch breaks and even when you have to take your work home just so you can finish up then sun it all up and check if it is actually worth it.
Especially if the new task or new job is a new one, and not one you are familiar with, there might be a need to actually take time to study and familiarize yourself with the new task so you can know what to do to not overwork yourself.
Trying to familiarize yourself with it would also show how often the job gets tedious and what time you can get engrossed with work or learn how to readjust your to-do lists.
Eventually after this evaluation you discover you are still working overtime or doing extra jobs and all just to be in form, then it might be time to consider making some changes.
Sometimes when you do some overtime at work or work extra than required it might be sending a message to your boss that you definitely can handle something higher than your role or probably you are saying indirectly how efficient you are in the job.
The disadvantages of working overtime would certainly be emphasized when it is seen as an expectation instead of seen as an exception or a choice. Then there are certainly some disadvantages that are cored to it .
* Long term overtime would certainly be detrimental to you in a whole lot of ways. It would definitely unbalance your work life and certainly destabilize the scale of balancing your work and personal life. Eventually you begin to lose productivity and lack results for working so hard. You get fired up and stressed at the end of each day.It would eventually come back and affect you as this is an increased stress and workload for you.
* If you consistently work till late, your manager or boss can begin to question your efficiency and capabilities during the day and probably make you feel lazy and cause the imposter syndrome to you eventually.
* If you certainly accept to do more work and simply tag it as a criteria under your job and you do it for free , eventually when you try to renegotiate with your boss on this issue, it might not speak so well because you already took the job willingly from the scratch so your boss would ask you why now ?
However working overtime sometimes might be of advantage and as earlier said it could be strategic in making your boss believe you are certainly capable of handling a higher workload than you are at the moment but then the moment multi-tasking seems detrimental to your health and your productivity, then it is time to negotiate with your boss and discuss with your boss.
* You need to be detailed and specific about how many extra hours you put into the work everyday and how it affects your time. Surprisingly your boss might not be aware of the overtime you are currently running.
* Inform your boss of how much of a high expectation kind of person that you are and how the under expectation results seems detrimental to you and suggests conditions that can aid you to meet up to personal and company expectation
After all of these negotiations with your boss, eventually you would be appreciated duly by the company for the overtime you do either by promotion or increase in salary.