It depends on how many workers your employer has. If there are 6 or more employees, this law goes into effect on January 1st, 2017. Employers that have five or fewer employees (who are employed for an average of no less than 30 hours per week) are not required to offer this benefit until January 1, 2018.
For future reference: New businesses will have a one-year grace period starting from the the date of their first hire.
*Employers may require a 1 year waiting period for new hires. If your employer does this, you can accrue sick time, but you cannot use it until the end of the probationary period.