DateTime到UNIX时间戳:

public static double DateTimeToUnixTimestamp(DateTime dateTime)
{
    return (TimeZoneInfo.ConvertTimeToUtc(dateTime) - 
           new DateTime(1970, 1, 1, 0, 0, 0, 0, System.DateTimeKind.Utc)).TotalSeconds;
}

Unix时间转换是. net Framework 4.6中的新功能。

现在，您可以更轻松地将日期和时间值转换为. net Framework类型和Unix时间。这可能是必要的，例如，在JavaScript客户机和. net服务器之间转换时间值时。DateTimeOffset结构中添加了以下api:

static DateTimeOffset FromUnixTimeSeconds(long seconds)
static DateTimeOffset FromUnixTimeMilliseconds(long milliseconds)
long DateTimeOffset.ToUnixTimeSeconds()
long DateTimeOffset.ToUnixTimeMilliseconds()

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);
    }
}

我需要将包含UNIX时间的timeval结构体(秒，微秒)转换为DateTime而不损失精度，在这里还没有找到答案，所以我想我只是可能会添加我的:

DateTime _epochTime = new DateTime(1970, 1, 1, 0, 0, 0, DateTimeKind.Utc);
private DateTime UnixTimeToDateTime(Timeval unixTime)
{
    return _epochTime.AddTicks(
        unixTime.Seconds * TimeSpan.TicksPerSecond +
        unixTime.Microseconds * TimeSpan.TicksPerMillisecond/1000);
}

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);
    }
}

Unix tick是1秒(如果我没记错的话)，net tick是100纳秒。

如果您遇到纳秒的问题，您可能想尝试使用AddTick(10000000 * value)。