A utility helper class for converting 64-bit ticks to doubles with minimal loss of precision

TimeConverter.cs

using System;

static class TimeConverter
{
    const double SecondsPerTick = 1.0 / TimeSpan.TicksPerSecond;

    public static double GetTimestamp(TimeSpan timeSpan)
    {
        return GetTimestamp(timeSpan.Ticks);
    }

    public static double GetTimestamp(long ticks)
    {
        var integral = (ticks / TimeSpan.TicksPerSecond) * TimeSpan.TicksPerSecond;
        var fractional = ticks - integral;
        return (integral * SecondsPerTick) +
               (fractional * SecondsPerTick);
    }

    public static long ToTicks(double seconds)
    {
        var integral = Math.Truncate(seconds);
        var fractional = seconds - integral;
        return (long)(integral * TimeSpan.TicksPerSecond) +
               (long)(fractional * TimeSpan.TicksPerSecond);
    }

    public static TimeSpan ToTimeSpan(double seconds)
    {
        return new TimeSpan(ToTicks(seconds));
    }
}