我怎么知道特定日期是一个月还是一个星期到父母日期？

Question

假设我有一个程序可以提醒用户他们的约会，从当前日期到约会日期，我想知道特定日期是约会的一周还是约会的一个月。

var startDate = startDate
let calendar = Calendar.current

let fmt = DateFormatter()
fmt.dateFormat = "yyyy-MM-dd"

while startDate <= endDate {

    var  newDate = calendar.date(byAdding: .day, value: 1, to: startDate)!


    if newDate is a month to endDate {

        //schedule reminder
    }

    if newDate is a week to endDate{

        //schedule reminder
    }

我如何检查当前日期是否是约会的一周/一个月？

Answer 1

您不需要使用任何日期比较，您可以简单地使用Calendar.date(byAdding:value:to:)生成通知日期并传递正确的组件。 要在endDate之前 1 周/月设置日期，请将-1传递给值。

let oneWeekBeforeAppointment = Calendar.current.date(byAdding: .weekOfYear, value: -1, to: endDate)!
let oneMonthBeforeAppointment = Calendar.current.date(byAdding: .month, value: -1, to: endDate)!

Answer 2

试试这个来计算以天为单位的持续时间

func DateFormat() -> DateFormatter {
  let dateFormatter = DateFormatter()
  dateFormatter.dateFormat = "dd/MM/yyyy"
  dateFormatter.timeZone = TimeZone(abbreviation: "GMT")
  return dateFormatter
}

var appointementDate: Date?
var today = Date()

appointementDate = DateFormat().date(from: "22/02/2020")
today = DateFormat().date(from: DateFormat().string(from: today))!

let timeInterval = Int(exactly: (today.timeIntervalSince(appointementDate!))) ?? 0
print("\(timeInterval/86400) days left")