Change in Work Hours: An Employer's Right - The Maryland Guide to Wage Payment and Employment Standards
In the absence of an employment contract, agreement or policy which states otherwise, an employer may shorten or lengthen an employee's work hours, or change the shift or times for employment, at any time at the employer's discretion.
Note: Generally, qualifying employees who work more than 40 hours in a work week must be paid time and one-half for overtime.