In todays day and age, you can organize payments to be made in advance. If you are a salary earner there is NO excuse for delay in payments. If he is not paying you on time its either because of 3 things:
1.) He doesnt care, in which case you need to find a new job because I wouldnt work for a boss who doesnt appreciate my contribution to the company.
2.) he doesnt have the money, which means you should get out! Because its only a matter of time till he he wont pay you at all, for a month or permanently.
3.) He takes it for granted that you are frum and so is he thus he expects you to indulge his disorganization. In this case you need to remind him of the fact that majority of the gemarah focuses on payments and property- because in Judaism we take these things seriously! And this is also a business so it must be run professionally.