﻿ 计算时间戳的公式是什么？ - 代码日志

#### 计算时间戳的公式是什么？

``````public static Int64 GetTimeStamp(
int year, int month, int day,
int hour, int minute, int second, int milliseconds)
{
Int64 timestamp = DateToTicks(year, month, day)
+ TimeToTicks(hour, minute, second);

return timestamp + milliseconds * TicksInMillisecond;
}

static readonly int[] DaysToMonth365 =
new int[] { 0, 31, 59, 90, 120, 151, 181, 212, 243, 273, 304, 334, 365 };
static readonly int[] DaysToMonth366 =
new int[] { 0, 31, 60, 91, 121, 152, 182, 213, 244, 274, 305, 335, 366 };
const long TicksInSecond = TicksInMillisecond * 1000L;
const long TicksInMillisecond = 10000L;

public static bool IsLeapYear(int year)
{
if ((year < 1) || (year > 9999))
throw new ArgumentOutOfRangeException("year", "Bad year.");

if ((year % 4) != 0)
return false;

if ((year % 100) == 0)
return ((year % 400) == 0);

return true;
}

private static long DateToTicks(int year, int month, int day)
{
if (((year >= 1) && (year <= 9999)) && ((month >= 1) && (month <= 12)))
{
int[] daysToMonth = IsLeapYear(year) ? DaysToMonth366 : DaysToMonth365;
if ((day >= 1) && (day <= (daysToMonth[month] - daysToMonth[month - 1])))
{
int previousYear = year - 1;
int daysInPreviousYears = ((((previousYear * 365) + (previousYear / 4)) - (previousYear / 100)) + (previousYear / 400));

int totalDays = ((daysInPreviousYears + daysToMonth[month - 1]) + day) - 1;
return (totalDays * 0xc92a69c000L);
}
}
throw new ArgumentOutOfRangeException();
}

private static long TimeToTicks(int hour, int minute, int second)
{
long totalSeconds = ((hour * 3600L) + (minute * 60L)) + second;
if ((totalSeconds > 0xd6bf94d5e5L) || (totalSeconds < -922337203685L))
throw new ArgumentOutOfRangeException();

return (totalSeconds * TicksInSecond);
}
``````