如何在swift 4 中获取今天和明天的日期

Question

如何获取unix-epoch中的当前日期？ timeIntervalSince1970 打印当前时间。有什么办法可以得到今天中午 12 点的时间吗？

例如，当前时间是：2018 年 1 月 7 日 5:30 下午。 timeIntervalSince1970 将打印当前时间，即 1546903800000。纪元系统中的当前日期为 2018 年 1 月 7 日 00:00 AM。即 1546848000000

Answer 1

我会用组件来做。

假设您需要 time(2). If you need in milliseconds as defined by time(3) 定义的以秒为单位的时间，那么您可以将其乘以 1000。

// Get right now as it's `DateComponents`.
let now = Calendar.current.dateComponents(in: .current, from: Date())

// Create the start of the day in `DateComponents` by leaving off the time.
let today = DateComponents(year: now.year, month: now.month, day: now.day)
let dateToday = Calendar.current.date(from: today)!
print(dateToday.timeIntervalSince1970)

// Add 1 to the day to get tomorrow.
// Don't worry about month and year wraps, the API handles that.
let tomorrow = DateComponents(year: now.year, month: now.month, day: now.day! + 1)
let dateTomorrow = Calendar.current.date(from: tomorrow)!
print(dateTomorrow.timeIntervalSince1970)

昨天减1即可

如果你在世界时需要这个（UTC、GMT、Z……无论你给世界时起什么名字），然后使用下面的。

let utc = TimeZone(abbreviation: "UTC")!
let now = Calendar.current.dateComponents(in: utc, from: Date())

Answer 2

这可以使用以下代码非常简单地完成。不需要日期组件或其他并发症。

var calendar = Calendar.current
// Use the following line if you want midnight UTC instead of local time
//calendar.timeZone = TimeZone(secondsFromGMT: 0)
let today = Date()
let midnight = calendar.startOfDay(for: today)
let tomorrow = calendar.date(byAdding: .day, value: 1, to: midnight)!

let midnightEpoch = midnight.timeIntervalSince1970
let tomorrowEpoch = tomorrow.timeIntervalSince1970

Answer 3

也尝试在日期扩展中添加以下代码：

extension Date
{
    var startOfDay: Date 
    {
        return Calendar.current.startOfDay(for: self)
    }

    func getDate(dayDifference: Int) -> Date {
        var components = DateComponents()
        components.day = dayDifference
        return Calendar.current.date(byAdding: components, to:startOfDay)!
    }
}

Answer 4

您可以使用以下方法通过添加天或月或年来获取任何日期通过指定日历组件和该组件的增量值：

func getSpecificDate(byAdding component: Calendar.Component, value: Int) -> Date {

    let noon = Calendar.current.date(bySettingHour: 12, minute: 0, second: 0, of: self)!

    return Calendar.current.date(byAdding: component, value: value, to: noon)!
}

组件将是以下选项之一： ( .day , .month , .year ) 并且该值将是您要为此组件添加的金额

例如，要获取下一年的日期，您可以使用以下代码：

var nextYear = getSpecificDate(byAdding: .year, value: 1).timeIntervalSince1970

Answer 5

使用此扩展程序获取今天和明天的日期

extension Date {
   static var tomorrow:  Date { return Date().dayAfter }
   static var today: Date {return Date()}
   var dayAfter: Date {
      return Calendar.current.date(byAdding: .day, value: 1, to: Date())!
   }
}

如何在swift 4 中获取今天和明天的日期

How to get the today's and tomorrow's date in swift 4

time

ios

swift

swift4