比较两个NSDates并忽略时间组件

import Foundation

let date1 = NSDate()
let date2 = NSDate()

let calendar = Calendar.current
let dateComponents1 = calendar.dateComponents([.year, .month, .day], from: date1 as Date)
let dateComponents2 = calendar.dateComponents([.year, .month, .day], from: date2 as Date)

if dateComponents1 == dateComponents2 {
    print("两个日期相同")
} else if dateComponents1< dateComponents2 {
    print("第一个日期早于第二个日期")
} else {
    print("第一个日期晚于第二个日期")
}