TimeConstants.cs

public static class TimeConstants
{
    public const int MillisecondsPerSecond = 1000;
    public const int MillisecondsPerMinute = MillisecondsPerSecond * SecondsPerMinute;
    public const int MillisecondsPerHour = MillisecondsPerMinute * MinutesPerHour;
    public const int MillisecondsPerDay = MillisecondsPerHour * HoursPerDay;
    public const int MillisecondsPerWeek = MillisecondsPerDay * DaysPerWeek;

    public const int SecondsPerMinute = 60;
    public const int SecondsPerHour = SecondsPerMinute * MinutesPerHour;
    public const int SecondsPerDay = SecondsPerHour * HoursPerDay;
    public const int SecondsPerWeek = SecondsPerDay * DaysPerWeek;

    public const int MinutesPerHour = 60;
    public const int MinutesPerDay = MinutesPerHour * HoursPerDay;
    public const int MinutesPerWeek = MinutesPerDay * DaysPerWeek;

    public const int HoursPerDay = 24;
    public const int HoursPerWeek = HoursPerDay * DaysPerWeek;

    public const int DaysPerWeek = 7;
}