根据swift或objective-c中的GMT计算到次日0.00的时间间隔?

首先创建 Calendar 适用于UTC时区。第二,获取 startOfDay using the UTC calendar. Third add one day to that date. Then you can use 日期 method timeIntervalSince(\uDate)`计算这两个日期之间的秒数:

extension Calendar {
    static let iso8601UTC: Calendar = {
        var calendar = Calendar(identifier: .iso8601)
        calendar.timeZone = TimeZone(identifier: "UTC")!
        return calendar
    }()
}

extension Date {
    var secondsUntilStartOfDayTomorrowAtUTC: TimeInterval {
        return startOfDayTomorrowAtUTC.timeIntervalSince(self)
    }
    var startOfDayTomorrowAtUTC: Date {
        return Calendar.current.date(byAdding: .day, value: 1, to: startOfDayAtUTC)!
    }
    var startOfDayAtUTC: Date {
        return Calendar.iso8601UTC.startOfDay(for: self)
    }
}

操场测试:

TimeZone.current.secondsFromGMT(for: Date()) / 3600 // -2 hours
Date().startOfDayAtUTC          // "Jan 18, 2018 at 10:00 PM"
let finalDate = Date().startOfDayTomorrowAtUTC  // "Jan 19, 2018 at 10:00 PM"
print(finalDate)  // "2018-01-20 00:00:00 +0000\n"
let seconds = Date().secondsUntilStartOfDayTomorrowAtUTC  // 29282.42592203617
let minutes = seconds / 60   // 488.0404320339362
let hours = seconds / 3600   // 8.134007200565604

例如,当我将小时设置为0时,它会根据GMT显示(在我的情况下,它是3小时的差值)。当我计算两个日期之间的差异时,两个日期都有相同的“位移”,所以最终结果应该是相同的