Shift scheduling emerged as the latest battleground in US labor relations in April 2015 as a California federal judge and New York State Attorney General Eric Schneiderman put on-call shifts, or call-in shifts, at the forefront of the ongoing public discourse on employee relations. On-call shifts (not to be confused with on-call time, discussed below) require an employee to call in to work prior to the start of a tentatively scheduled shift to find out whether he or she needs to report for work. Call-in lead times vary from one employer to the next, but employees are typically required to call the employer between a few days to a few hours before the scheduled shift.