SAN FRANCISCO—San Francisco has become the first city in the country to offer six paid weeks of parental leave. The city is also the first to offer full paid parental leave. A proposal was voted by the San Francisco Board of Supervisors to allow parents to take six weeks of parental leave at 100 percent of their salary; 55 percent covered by the state and 45 percent covered by companies with 20 or more employees.

Small business owners oppose the legislation. “They don’t necessarily have the resources,” Dee Dee Workman, vice president of public policy at the San Francisco Chamber of Commerce, told The Associated Press. “They can’t absorb the increases in cost.”

Scott Weiner one of the members of the Board of Supervisors, wrote on Twitter that, “Board of Supervisors unanimously passed my #PaidParentalLeave legislation; makes SF 1st place in US to guarantee 6 fully paid weeks of leave.” The approved legislation would take effect in 2017. The U.S. is the only developed country that doesn’t have mandatory paid family leave.

Once the law is fully enacted partners of new moms will have 12 weeks of paid time to care for a new baby. The Family and Medical Act allows Americans the right to take three months of unpaid leave. Those working in the technology sector and high-income earners usually have parental leave with sustainable income. The new approved legislation also applies to parents that adopt. The new legislation will undergo another formal vote then be signed in by Mayor Lee.

“The vast majority of workers in this country have little or no access to paid parental leave, and that needs to change,” said Supervisor Scott Wiener, a proponent of the rule, at a news conference.

On Twitter many people commented their feelings on the new approved legislation. Twitter user Josh Silverman wrote, “This is progress. Your move, Mississippi and North Carolina.”

Twitter just announced that it would offer equal time to both mothers and fathers expecting new babies. Parents would be able to take 20 weeks off work with full pay. The rule would cover adoptions. The rule would take affect at the end of April.