What is the expiring time for a work permit produced from Bulgaria

Hello,
To get a work permit for Bulgaria if you are not from an EU country (EU citizens don't need one) or you are not a family member of a Bulgarian/EU citizen, you'd first need to find a job in Bulgaria. When this happens, your employer will apply for your work permit. There are different types of work permits with different duration periods, and the Labor Agency decides the duration for each work permit separately. So even if the longest possible period is 4 years, they can decide to give you 3 or 2 years. Therefore, there isn't a straight answer to your question. It depends first on the type of work permit you will apply for and second on the decision of the Labor Agency. ***

Hi, thanks a lot for your answer.by the way I already got a job offer from Bulgaria and the agency granded the work permit,now they need to send the original work permit to me.my doubt is within how many days do I need to file my visa application in the embassy (because the legal agency in Bulgaria,they will take time to send me the work permit,one of my friend got job in malta and they took around 55days to send the work permit,so the embassy rejected the application due to the expiry of work permit in malta is 60 days.. I need to know the expiring period of Bulgarian work permit.thank you