这里有一个示例代码，但是它开始讨论毫秒/纳秒的问题。
同样的问题出现在MSDN上，从c#的Unix时代开始。
这是我目前得到的:
public Double CreatedEpoch
{
get
{
DateTime epoch = new DateTime(1970, 1, 1, 0, 0, 0, 0).ToLocalTime();
TimeSpan span = (this.Created.ToLocalTime() - epoch);
return span.TotalSeconds;
}
set
{
DateTime epoch = new DateTime(1970, 1, 1, 0, 0, 0, 0).ToLocalTime();
this.Created = epoch.AddSeconds(value);
}
}
当前回答
看到IdentityModel。EpochTimeExtensions
public static class EpochTimeExtensions
{
/// <summary>
/// Converts the given date value to epoch time.
/// </summary>
public static long ToEpochTime(this DateTime dateTime)
{
var date = dateTime.ToUniversalTime();
var ticks = date.Ticks - new DateTime(1970, 1, 1, 0, 0, 0, 0, DateTimeKind.Utc).Ticks;
var ts = ticks / TimeSpan.TicksPerSecond;
return ts;
}
/// <summary>
/// Converts the given date value to epoch time.
/// </summary>
public static long ToEpochTime(this DateTimeOffset dateTime)
{
var date = dateTime.ToUniversalTime();
var ticks = date.Ticks - new DateTimeOffset(1970, 1, 1, 0, 0, 0, TimeSpan.Zero).Ticks;
var ts = ticks / TimeSpan.TicksPerSecond;
return ts;
}
/// <summary>
/// Converts the given epoch time to a <see cref="DateTime"/> with <see cref="DateTimeKind.Utc"/> kind.
/// </summary>
public static DateTime ToDateTimeFromEpoch(this long intDate)
{
var timeInTicks = intDate * TimeSpan.TicksPerSecond;
return new DateTime(1970, 1, 1, 0, 0, 0, 0, DateTimeKind.Utc).AddTicks(timeInTicks);
}
/// <summary>
/// Converts the given epoch time to a UTC <see cref="DateTimeOffset"/>.
/// </summary>
public static DateTimeOffset ToDateTimeOffsetFromEpoch(this long intDate)
{
var timeInTicks = intDate * TimeSpan.TicksPerSecond;
return new DateTimeOffset(1970, 1, 1, 0, 0, 0, TimeSpan.Zero).AddTicks(timeInTicks);
}
}
其他回答
为了补充ScottCher的回答，我最近发现自己遇到了一种令人讨厌的情况，即在输入数据集中将秒级和毫秒级的UNIX时间戳任意混合在一起。下面的代码似乎可以很好地处理这个问题:
static readonly DateTime UnixEpoch = new DateTime(1970, 1, 1, 0, 0, 0, 0, DateTimeKind.Utc);
static readonly double MaxUnixSeconds = (DateTime.MaxValue - UnixEpoch).TotalSeconds;
public static DateTime UnixTimeStampToDateTime(double unixTimeStamp)
{
return unixTimeStamp > MaxUnixSeconds
? UnixEpoch.AddMilliseconds(unixTimeStamp)
: UnixEpoch.AddSeconds(unixTimeStamp);
}
对于。net 4.6及更高版本:
public static class UnixDateTime
{
public static DateTimeOffset FromUnixTimeSeconds(long seconds)
{
if (seconds < -62135596800L || seconds > 253402300799L)
throw new ArgumentOutOfRangeException("seconds", seconds, "");
return new DateTimeOffset(seconds * 10000000L + 621355968000000000L, TimeSpan.Zero);
}
public static DateTimeOffset FromUnixTimeMilliseconds(long milliseconds)
{
if (milliseconds < -62135596800000L || milliseconds > 253402300799999L)
throw new ArgumentOutOfRangeException("milliseconds", milliseconds, "");
return new DateTimeOffset(milliseconds * 10000L + 621355968000000000L, TimeSpan.Zero);
}
public static long ToUnixTimeSeconds(this DateTimeOffset utcDateTime)
{
return utcDateTime.Ticks / 10000000L - 62135596800L;
}
public static long ToUnixTimeMilliseconds(this DateTimeOffset utcDateTime)
{
return utcDateTime.Ticks / 10000L - 62135596800000L;
}
[Test]
public void UnixSeconds()
{
DateTime utcNow = DateTime.UtcNow;
DateTimeOffset utcNowOffset = new DateTimeOffset(utcNow);
long unixTimestampInSeconds = utcNowOffset.ToUnixTimeSeconds();
DateTimeOffset utcNowOffsetTest = UnixDateTime.FromUnixTimeSeconds(unixTimestampInSeconds);
Assert.AreEqual(utcNowOffset.Year, utcNowOffsetTest.Year);
Assert.AreEqual(utcNowOffset.Month, utcNowOffsetTest.Month);
Assert.AreEqual(utcNowOffset.Date, utcNowOffsetTest.Date);
Assert.AreEqual(utcNowOffset.Hour, utcNowOffsetTest.Hour);
Assert.AreEqual(utcNowOffset.Minute, utcNowOffsetTest.Minute);
Assert.AreEqual(utcNowOffset.Second, utcNowOffsetTest.Second);
}
[Test]
public void UnixMilliseconds()
{
DateTime utcNow = DateTime.UtcNow;
DateTimeOffset utcNowOffset = new DateTimeOffset(utcNow);
long unixTimestampInMilliseconds = utcNowOffset.ToUnixTimeMilliseconds();
DateTimeOffset utcNowOffsetTest = UnixDateTime.FromUnixTimeMilliseconds(unixTimestampInMilliseconds);
Assert.AreEqual(utcNowOffset.Year, utcNowOffsetTest.Year);
Assert.AreEqual(utcNowOffset.Month, utcNowOffsetTest.Month);
Assert.AreEqual(utcNowOffset.Date, utcNowOffsetTest.Date);
Assert.AreEqual(utcNowOffset.Hour, utcNowOffsetTest.Hour);
Assert.AreEqual(utcNowOffset.Minute, utcNowOffsetTest.Minute);
Assert.AreEqual(utcNowOffset.Second, utcNowOffsetTest.Second);
Assert.AreEqual(utcNowOffset.Millisecond, utcNowOffsetTest.Millisecond);
}
}
如果您需要高于毫秒的精度，请小心!
. net (v4.6)方法(例如fromunixtimemillisecseconds)不提供这种精度。
AddSeconds和AddMilliseconds还截断了double中的微秒。
这些版本有很高的精度:
Unix -> DateTime
public static DateTime UnixTimestampToDateTime(double unixTime)
{
DateTime unixStart = new DateTime(1970, 1, 1, 0, 0, 0, 0, System.DateTimeKind.Utc);
long unixTimeStampInTicks = (long) (unixTime * TimeSpan.TicksPerSecond);
return new DateTime(unixStart.Ticks + unixTimeStampInTicks, System.DateTimeKind.Utc);
}
日期-> Unix
public static double DateTimeToUnixTimestamp(DateTime dateTime)
{
DateTime unixStart = new DateTime(1970, 1, 1, 0, 0, 0, 0, System.DateTimeKind.Utc);
long unixTimeStampInTicks = (dateTime.ToUniversalTime() - unixStart).Ticks;
return (double) unixTimeStampInTicks / TimeSpan.TicksPerSecond;
}
在c# 8.0(。NET Core 2.1)它是一个简单的一行代码:
DateTime.UnixEpoch.AddSeconds(unixTimeInSeconds)
以下是你需要的:
public static DateTime UnixTimeStampToDateTime( double unixTimeStamp )
{
// Unix timestamp is seconds past epoch
DateTime dateTime = new DateTime(1970, 1, 1, 0, 0, 0, 0, DateTimeKind.Utc);
dateTime = dateTime.AddSeconds( unixTimeStamp ).ToLocalTime();
return dateTime;
}
或者，对于Java(这是不同的，因为时间戳是以毫秒为单位的，而不是秒):
public static DateTime JavaTimeStampToDateTime( double javaTimeStamp )
{
// Java timestamp is milliseconds past epoch
DateTime dateTime = new DateTime(1970, 1, 1, 0, 0, 0, 0, DateTimeKind.Utc);
dateTime = dateTime.AddMilliseconds( javaTimeStamp ).ToLocalTime();
return dateTime;
}
