How do I represent a time only value in .NET?

Question

Is there a way one can represent a time only value in .NET without the date? For example, indicating the opening time of a shop?

TimeSpan indicates a range, whereas I only want to store a time value. Using DateTime to indicate this would result in new DateTime(1,1,1,8,30,0) which is not really desirable.

Answer 1

As others have said, you can use a DateTime and ignore the date, or use a TimeSpan. Personally I'm not keen on either of these solutions, as neither type really reflects the concept you're trying to represent - I regard the date/time types in .NET as somewhat on the sparse side which is one of the reasons I started Noda Time. In Noda Time, you can use the LocalTime type to represent a time of day.

One thing to consider: the time of day is not necessarily the length of time since midnight on the same day...

(As another aside, if you're also wanting to represent a closing time of a shop, you may find that you want to represent 24:00, i.e. the time at the end of the day. Most date/time APIs - including Noda Time - don't allow that to be represented as a time-of-day value.)

Answer 2

If that empty Date really bugs you, you can also to create a simpler Time structure:

// more work is required to make this even close to production ready
class Time
{
    // TODO: don't forget to add validation
    public int Hours   { get; set; }
    public int Minutes { get; set; }
    public int Seconds { get; set; }

    public override string ToString()
    {  
        return String.Format(
            "{0:00}:{1:00}:{2:00}",
            this.Hours, this.Minutes, this.Seconds);
    }
}

Or, why to bother: if you don't need to do any calculation with that information, just store it as String.

Answer 3

You can use timespan

TimeSpan timeSpan = new TimeSpan(2, 14, 18);
Console.WriteLine(timeSpan.ToString());     // Displays "02:14:18".

[Edit]
Considering the other answers and the edit to the question, I would still use TimeSpan. No point in creating a new structure where an existing one from the framework suffice.
On these lines you would end up duplicating many native data types.

Answer 4

I think Rubens' class is a good idea so thought to make an immutable sample of his Time class with basic validation.

class Time
{
    public int Hours   { get; private set; }
    public int Minutes { get; private set; }
    public int Seconds { get; private set; }

    public Time(uint h, uint m, uint s)
    {
        if(h > 23 || m > 59 || s > 59)
        {
            throw new ArgumentException("Invalid time specified");
        }
        Hours = (int)h; Minutes = (int)m; Seconds = (int)s;
    }

    public Time(DateTime dt)
    {
        Hours = dt.Hour;
        Minutes = dt.Minute;
        Seconds = dt.Second;
    }

    public override string ToString()
    {  
        return String.Format(
            "{0:00}:{1:00}:{2:00}",
            this.Hours, this.Minutes, this.Seconds);
    }
}

Answer 5

Here's a full featured TimeOfDay class.

This is overkill for simple cases, but if you need more advanced functionality like I did, this may help.

It can handle the corner cases, some basic math, comparisons, interaction with DateTime, parsing, etc.

Below is the source code for the TimeOfDay class. You can see usage examples and learn more here:

This class uses DateTime for most of its internal calculations and comparisons so that we can leverage all of the knowledge already embedded in DateTime.

// Author: Steve Lautenschlager, CambiaResearch.com
// License: MIT

using System;
using System.Text.RegularExpressions;

namespace Cambia
{
    public class TimeOfDay
    {
        private const int MINUTES_PER_DAY = 60 * 24;
        private const int SECONDS_PER_DAY = SECONDS_PER_HOUR * 24;
        private const int SECONDS_PER_HOUR = 3600;
        private static Regex _TodRegex = new Regex(@"\d?\d:\d\d:\d\d|\d?\d:\d\d");

        public TimeOfDay()
        {
            Init(0, 0, 0);
        }
        public TimeOfDay(int hour, int minute, int second = 0)
        {
            Init(hour, minute, second);
        }
        public TimeOfDay(int hhmmss)
        {
            Init(hhmmss);
        }
        public TimeOfDay(DateTime dt)
        {
            Init(dt);
        }
        public TimeOfDay(TimeOfDay td)
        {
            Init(td.Hour, td.Minute, td.Second);
        }

        public int HHMMSS
        {
            get
            {
                return Hour * 10000 + Minute * 100 + Second;
            }
        }
        public int Hour { get; private set; }
        public int Minute { get; private set; }
        public int Second { get; private set; }
        public double TotalDays
        {
            get
            {
                return TotalSeconds / (24d * SECONDS_PER_HOUR);
            }
        }
        public double TotalHours
        {
            get
            {
                return TotalSeconds / (1d * SECONDS_PER_HOUR);
            }
        }
        public double TotalMinutes
        {
            get
            {
                return TotalSeconds / 60d;
            }
        }
        public int TotalSeconds
        {
            get
            {
                return Hour * 3600 + Minute * 60 + Second;
            }
        }
        public bool Equals(TimeOfDay other)
        {
            if (other == null) { return false; }
            return TotalSeconds == other.TotalSeconds;
        }
        public override bool Equals(object obj)
        {
            if (obj == null) { return false; }
            TimeOfDay td = obj as TimeOfDay;
            if (td == null) { return false; }
            else { return Equals(td); }
        }
        public override int GetHashCode()
        {
            return TotalSeconds;
        }
        public DateTime ToDateTime(DateTime dt)
        {
            return new DateTime(dt.Year, dt.Month, dt.Day, Hour, Minute, Second);
        }
        public override string ToString()
        {
            return ToString("HH:mm:ss");
        }
        public string ToString(string format)
        {
            DateTime now = DateTime.Now;
            DateTime dt = new DateTime(now.Year, now.Month, now.Day, Hour, Minute, Second);
            return dt.ToString(format);
        }
        public TimeSpan ToTimeSpan()
        {
            return new TimeSpan(Hour, Minute, Second);
        }
        public DateTime ToToday()
        {
            var now = DateTime.Now;
            return new DateTime(now.Year, now.Month, now.Day, Hour, Minute, Second);
        }

        #region -- Static --
        public static TimeOfDay Midnight { get { return new TimeOfDay(0, 0, 0); } }
        public static TimeOfDay Noon { get { return new TimeOfDay(12, 0, 0); } }
        public static TimeOfDay operator -(TimeOfDay t1, TimeOfDay t2)
        {
            DateTime now = DateTime.Now;
            DateTime dt1 = new DateTime(now.Year, now.Month, now.Day, t1.Hour, t1.Minute, t1.Second);
            TimeSpan ts = new TimeSpan(t2.Hour, t2.Minute, t2.Second);
            DateTime dt2 = dt1 - ts;
            return new TimeOfDay(dt2);
        }
        public static bool operator !=(TimeOfDay t1, TimeOfDay t2)
        {
            if (ReferenceEquals(t1, t2)) { return true; }
            else if (ReferenceEquals(t1, null)) { return true; }
            else
            {
                return t1.TotalSeconds != t2.TotalSeconds;
            }
        }
        public static bool operator !=(TimeOfDay t1, DateTime dt2)
        {
            if (ReferenceEquals(t1, null)) { return false; }
            DateTime dt1 = new DateTime(dt2.Year, dt2.Month, dt2.Day, t1.Hour, t1.Minute, t1.Second);
            return dt1 != dt2;
        }
        public static bool operator !=(DateTime dt1, TimeOfDay t2)
        {
            if (ReferenceEquals(t2, null)) { return false; }
            DateTime dt2 = new DateTime(dt1.Year, dt1.Month, dt1.Day, t2.Hour, t2.Minute, t2.Second);
            return dt1 != dt2;
        }
        public static TimeOfDay operator +(TimeOfDay t1, TimeOfDay t2)
        {
            DateTime now = DateTime.Now;
            DateTime dt1 = new DateTime(now.Year, now.Month, now.Day, t1.Hour, t1.Minute, t1.Second);
            TimeSpan ts = new TimeSpan(t2.Hour, t2.Minute, t2.Second);
            DateTime dt2 = dt1 + ts;
            return new TimeOfDay(dt2);
        }
        public static bool operator <(TimeOfDay t1, TimeOfDay t2)
        {
            if (ReferenceEquals(t1, t2)) { return true; }
            else if (ReferenceEquals(t1, null)) { return true; }
            else
            {
                return t1.TotalSeconds < t2.TotalSeconds;
            }
        }
        public static bool operator <(TimeOfDay t1, DateTime dt2)
        {
            if (ReferenceEquals(t1, null)) { return false; }
            DateTime dt1 = new DateTime(dt2.Year, dt2.Month, dt2.Day, t1.Hour, t1.Minute, t1.Second);
            return dt1 < dt2;
        }
        public static bool operator <(DateTime dt1, TimeOfDay t2)
        {
            if (ReferenceEquals(t2, null)) { return false; }
            DateTime dt2 = new DateTime(dt1.Year, dt1.Month, dt1.Day, t2.Hour, t2.Minute, t2.Second);
            return dt1 < dt2;
        }
        public static bool operator <=(TimeOfDay t1, TimeOfDay t2)
        {
            if (ReferenceEquals(t1, t2)) { return true; }
            else if (ReferenceEquals(t1, null)) { return true; }
            else
            {
                if (t1 == t2) { return true; }
                return t1.TotalSeconds <= t2.TotalSeconds;
            }
        }
        public static bool operator <=(TimeOfDay t1, DateTime dt2)
        {
            if (ReferenceEquals(t1, null)) { return false; }
            DateTime dt1 = new DateTime(dt2.Year, dt2.Month, dt2.Day, t1.Hour, t1.Minute, t1.Second);
            return dt1 <= dt2;
        }
        public static bool operator <=(DateTime dt1, TimeOfDay t2)
        {
            if (ReferenceEquals(t2, null)) { return false; }
            DateTime dt2 = new DateTime(dt1.Year, dt1.Month, dt1.Day, t2.Hour, t2.Minute, t2.Second);
            return dt1 <= dt2;
        }
        public static bool operator ==(TimeOfDay t1, TimeOfDay t2)
        {
            if (ReferenceEquals(t1, t2)) { return true; }
            else if (ReferenceEquals(t1, null)) { return true; }
            else { return t1.Equals(t2); }
        }
        public static bool operator ==(TimeOfDay t1, DateTime dt2)
        {
            if (ReferenceEquals(t1, null)) { return false; }
            DateTime dt1 = new DateTime(dt2.Year, dt2.Month, dt2.Day, t1.Hour, t1.Minute, t1.Second);
            return dt1 == dt2;
        }
        public static bool operator ==(DateTime dt1, TimeOfDay t2)
        {
            if (ReferenceEquals(t2, null)) { return false; }
            DateTime dt2 = new DateTime(dt1.Year, dt1.Month, dt1.Day, t2.Hour, t2.Minute, t2.Second);
            return dt1 == dt2;
        }
        public static bool operator >(TimeOfDay t1, TimeOfDay t2)
        {
            if (ReferenceEquals(t1, t2)) { return true; }
            else if (ReferenceEquals(t1, null)) { return true; }
            else
            {
                return t1.TotalSeconds > t2.TotalSeconds;
            }
        }
        public static bool operator >(TimeOfDay t1, DateTime dt2)
        {
            if (ReferenceEquals(t1, null)) { return false; }
            DateTime dt1 = new DateTime(dt2.Year, dt2.Month, dt2.Day, t1.Hour, t1.Minute, t1.Second);
            return dt1 > dt2;
        }
        public static bool operator >(DateTime dt1, TimeOfDay t2)
        {
            if (ReferenceEquals(t2, null)) { return false; }
            DateTime dt2 = new DateTime(dt1.Year, dt1.Month, dt1.Day, t2.Hour, t2.Minute, t2.Second);
            return dt1 > dt2;
        }
        public static bool operator >=(TimeOfDay t1, TimeOfDay t2)
        {
            if (ReferenceEquals(t1, t2)) { return true; }
            else if (ReferenceEquals(t1, null)) { return true; }
            else
            {
                return t1.TotalSeconds >= t2.TotalSeconds;
            }
        }
        public static bool operator >=(TimeOfDay t1, DateTime dt2)
        {
            if (ReferenceEquals(t1, null)) { return false; }
            DateTime dt1 = new DateTime(dt2.Year, dt2.Month, dt2.Day, t1.Hour, t1.Minute, t1.Second);
            return dt1 >= dt2;
        }
        public static bool operator >=(DateTime dt1, TimeOfDay t2)
        {
            if (ReferenceEquals(t2, null)) { return false; }
            DateTime dt2 = new DateTime(dt1.Year, dt1.Month, dt1.Day, t2.Hour, t2.Minute, t2.Second);
            return dt1 >= dt2;
        }
        /// <summary>
        /// Input examples:
        /// 14:21:17            (2pm 21min 17sec)
        /// 02:15               (2am 15min 0sec)
        /// 2:15                (2am 15min 0sec)
        /// 2/1/2017 14:21      (2pm 21min 0sec)
        /// TimeOfDay=15:13:12  (3pm 13min 12sec)
        /// </summary>
        public static TimeOfDay Parse(string s)
        {
            // We will parse any section of the text that matches this
            // pattern: dd:dd or dd:dd:dd where the first doublet can
            // be one or two digits for the hour.  But minute and second
            // must be two digits.

            Match m = _TodRegex.Match(s);
            string text = m.Value;
            string[] fields = text.Split(':');
            if (fields.Length < 2) { throw new ArgumentException("No valid time of day pattern found in input text"); }
            int hour = Convert.ToInt32(fields[0]);
            int min = Convert.ToInt32(fields[1]);
            int sec = fields.Length > 2 ? Convert.ToInt32(fields[2]) : 0;

            return new TimeOfDay(hour, min, sec);
        }
        #endregion

        private void Init(int hour, int minute, int second)
        {
            if (hour < 0 || hour > 23) { throw new ArgumentException("Invalid hour, must be from 0 to 23."); }
            if (minute < 0 || minute > 59) { throw new ArgumentException("Invalid minute, must be from 0 to 59."); }
            if (second < 0 || second > 59) { throw new ArgumentException("Invalid second, must be from 0 to 59."); }
            Hour = hour;
            Minute = minute;
            Second = second;
        }
        private void Init(int hhmmss)
        {
            int hour = hhmmss / 10000;
            int min = (hhmmss - hour * 10000) / 100;
            int sec = (hhmmss - hour * 10000 - min * 100);
            Init(hour, min, sec);
        }
        private void Init(DateTime dt)
        {
            Init(dt.Hour, dt.Minute, dt.Second);
        }
    }
}

Answer 6

In addition to Chibueze Opata:

class Time
{
    public int Hours   { get; private set; }
    public int Minutes { get; private set; }
    public int Seconds { get; private set; }

    public Time(uint h, uint m, uint s)
    {
        if(h > 23 || m > 59 || s > 59)
        {
            throw new ArgumentException("Invalid time specified");
        }
        Hours = (int)h; Minutes = (int)m; Seconds = (int)s;
    }

    public Time(DateTime dt)
    {
        Hours = dt.Hour;
        Minutes = dt.Minute;
        Seconds = dt.Second;
    }

    public override string ToString()
    {  
        return String.Format(
            "{0:00}:{1:00}:{2:00}",
            this.Hours, this.Minutes, this.Seconds);
    }

    public void AddHours(uint h)
    {
        this.Hours += (int)h;
    }

    public void AddMinutes(uint m)
    {
        this.Minutes += (int)m;
        while(this.Minutes > 59)
            this.Minutes -= 60;
            this.AddHours(1);
    }

    public void AddSeconds(uint s)
    {
        this.Seconds += (int)s;
        while(this.Seconds > 59)
            this.Seconds -= 60;
            this.AddMinutes(1);
    }
}