// The start of a week for 2 September 2014 11:55:00: var result = startOfWeek(new Date(2014, 8, 2, 11, 55, 0)) //=> Sun Aug 31 2014 00:00:00

// If the week starts on Monday, the start of the week for 2 September 2014 11:55:00: var result = startOfWeek(new Date(2014, 8, 2, 11, 55, 0), { weekStartsOn: 1 }) //=> Mon Sep 01 2014 00:00:00