Yes, assuming the specific requirements set out below are met, you may be entitle to take religious holiday.  Also, if your boss allows you to skip work because of a holy day, she can require you to make the time up.  For this information, and a complete explanation of your rights and and your employers responsibilities, I have reprinted below 804 CMR 3.01(7)(b):

(b) Reasonable Accommodation to the Religious Needs of Employees or Prospective Employees.

1. It is unlawful for an employer to impose upon an employee or prospective employee as a condition of obtaining or retaining employment any terms or conditions which would require the individual to violate or forego a practice required by his or her religion. This includes but is not limited to requiring an employee or prospective employee to work on any day or portion thereof that the employee observes as a sabbath or holy day.

 
a. In requesting an absence for religious purposes, the employee or prospective employee:

         
i. must demonstrate that observance of the sabbath or holy day is a required practice of his or her religion;

         
ii. must notify his or her employer at least ten days in advance of the requested absence that he or she intends to take the absence for religious purposes;

iii. may include a reasonable amount of time for travel to and from work in the request for time of

b. The employer may require the employee to make up the absence at a mutually convenient time.

c. The employer is not required to compensate an employee for any religious absence requested in accordance with the requirements of the statute.

2. The employee shall have the burden of proof as to the required practices of his or her religion.

3. An employer shall make reasonable accommodation to the religious needs of employees or prospective employees provided that such accommodation shall not pose an undue hardship in the conduct of the employer's business.

  
a. Examples of undue hardship include:

i. Inability to provide services which are required by federal or state law or regulation;

ii. Situations which compromise public health and safety;

iii. Inability to transact business without the employee's presence, where his or her work cannot be performed by another employee who has substantially similar qualifications during the period of absence;

iv. The employee's presence is needed to alleviate an emergency situation.

b. It is the employer's burden to demonstrate that making the accommodation poses an undue hardship.

Hope that helps.  For more information or to post a question, visit our MA Employment Law Discussion Forum.