вкладки у основания TabControl

Для расчета сдвига вы можете использовать этот код

class ShiftInfo : IEquatable
{
    public ShiftInfo(TimeSpan startTime, string name)
    {
        this.StartTime = startTime;
        this.Name = name;
    }

    public TimeSpan StartTime
    {
        get;
        private set;
    }

    public string Name
    {
        get;
        private set;
    }

    public bool Equals(ShiftInfo other)
    {
        return StartTime.Equals(other.StartTime);
    }

    public override bool Equals(object obj)
    {
        if (obj == null)
        {
            return false;
        }

        if (obj is ShiftInfo)
        {
            return this.Equals((ShiftInfo)obj);
        }

        return false;
    }

    public override int GetHashCode()
    {
        return StartTime.GetHashCode();
    }
}

class ShiftConfig : IEnumerable
{
    private readonly ICollection _shiftInfos;
    public ShiftConfig(params ShiftInfo[] shiftInfos)
    {
        _shiftInfos = shiftInfos.Distinct().OrderBy(e => e.StartTime).ToList();
    }

    public ShiftConfig(HashSet shiftInfos)
    {
        _shiftInfos = shiftInfos.OrderBy(e => e.StartTime).ToList();
    }

    public IEnumerator GetEnumerator()
    {
        return _shiftInfos.GetEnumerator();
    }

    IEnumerator IEnumerable.GetEnumerator()
    {
        return _shiftInfos.GetEnumerator();
    }
}

class ShiftWorkItem
{
    public ShiftWorkItem(ShiftInfo shift, DateTime shiftFrom, DateTime shiftUntil, DateTime workFrom, DateTime workUntil)
    {
        Shift = shift;
        ShiftFrom = shiftFrom;
        ShiftUntil = shiftUntil;
        WorkFrom = workFrom;
        WorkUntil = workUntil;
    }

    public ShiftInfo Shift
    {
        get;
        private set;
    }

    public DateTime ShiftFrom
    {
        get;
        private set;
    }

    public DateTime ShiftUntil
    {
        get;
        private set;
    }

    public TimeSpan ShiftDuration
    {
        get
        {
            return ShiftUntil - ShiftFrom;
        }
    }

    public DateTime WorkFrom
    {
        get;
        private set;
    }

    public DateTime WorkUntil
    {
        get;
        private set;
    }

    public TimeSpan WorkDuration
    {
        get
        {
            return WorkUntil - WorkFrom;
        }
    }
}

static class ShiftConfigExtensions
{
    public static IEnumerable EnumerateShifts(this ShiftConfig config, DateTime from, TimeSpan duration)
    {
        return EnumerateShifts(config, from, from.Add(duration));
    }

    public static IEnumerable EnumerateShifts(this ShiftConfig config, DateTime from, DateTime until)
    {
        DateTime day = from.Date.AddDays(-1);
        DateTime? shiftStart = null;
        ShiftInfo lastShift = null;
        while (true)
        {
            foreach (var shift in config)
            {
                var shiftEnd = day.Add(shift.StartTime);
                if (shiftStart != null)
                {
                    if ((shiftStart.Value <= from && shiftEnd >= from) || (shiftStart.Value <= until && shiftEnd >= until) || (shiftStart.Value > from && shiftEnd <= until))
                    {
                        var workFrom = shiftStart.Value < from ? from : shiftStart.Value;
                        var workUntil = shiftEnd > until ? until : shiftEnd;
                        yield return new ShiftWorkItem(lastShift, shiftStart.Value, shiftEnd, workFrom, workUntil);
                    }
                }

                if (shiftEnd >= until)
                {
                    yield break;
                }

                shiftStart = shiftEnd;
                lastShift = shift;
            }

            day = day.AddDays(1);
        }
    }
}

Использование

public static void Main(string[] args)
{
    var sc = new ShiftConfig(
        new ShiftInfo(TimeSpan.FromHours(6), "early"), 
        new ShiftInfo(TimeSpan.FromHours(14), "late"), 
        new ShiftInfo(TimeSpan.FromHours(22), "night"));
    Console.WriteLine("                      |          SHIFT          |          WORK           ");
    Console.WriteLine("   Date    Shiftname  |   from    until   dur.  |   from    until   dur.  ");
    Console.WriteLine("======================|=========================|=========================");
    foreach (var item in sc.EnumerateShifts(new DateTime(2019, 01, 01, 02, 37, 25), TimeSpan.FromHours(28.34)))
    {
        Console.WriteLine("{0:yyyy-MM-dd} {1,-10} | {2:HH:mm:ss} {3:HH:mm:ss} {4:0.00}h | {5:HH:mm:ss} {6:HH:mm:ss} {7:0.00}h", item.ShiftFrom.Date, item.Shift.Name, item.ShiftFrom, item.ShiftUntil, item.ShiftDuration.TotalHours, item.WorkFrom, item.WorkUntil, item.WorkDuration.TotalHours);
    }
}

, который генерирует

                      |          SHIFT          |          WORK           
   Date    Shiftname  |   from    until   dur.  |   from    until   dur.  
======================|=========================|=========================
2018-12-31 night      | 22:00:00 06:00:00 8.00h | 02:37:25 06:00:00 3.38h
2019-01-01 early      | 06:00:00 14:00:00 8.00h | 06:00:00 14:00:00 8.00h
2019-01-01 late       | 14:00:00 22:00:00 8.00h | 14:00:00 22:00:00 8.00h
2019-01-01 night      | 22:00:00 06:00:00 8.00h | 22:00:00 06:00:00 8.00h
2019-01-02 early      | 06:00:00 14:00:00 8.00h | 06:00:00 06:57:49 0.96h

.net fiddle sample [115 ]

или для покрытия вашего образца

public static void Main(string[] args)
{
    var sc = new ShiftConfig(
        new ShiftInfo(TimeSpan.FromHours(0), "night"), 
        new ShiftInfo(TimeSpan.FromHours(8), "early"), 
        new ShiftInfo(TimeSpan.FromHours(16), "late"));
    Console.WriteLine("                      |          SHIFT          |          WORK           ");
    Console.WriteLine("   Date    Shiftname  |   from    until   dur.  |   from    until   dur.  ");
    Console.WriteLine("======================|=========================|=========================");
    foreach (var item in sc.EnumerateShifts(new DateTime(2019, 01, 01, 15, 55, 00), TimeSpan.FromMinutes(20)))
    {
        Console.WriteLine("{0:yyyy-MM-dd} {1,-10} | {2:HH:mm:ss} {3:HH:mm:ss} {4:0.00}h | {5:HH:mm:ss} {6:HH:mm:ss} {7:0.00}h", item.ShiftFrom.Date, item.Shift.Name, item.ShiftFrom, item.ShiftUntil, item.ShiftDuration.TotalHours, item.WorkFrom, item.WorkUntil, item.WorkDuration.TotalHours);
    }
}

мы получаем

                      |          SHIFT          |          WORK           
   Date    Shiftname  |   from    until   dur.  |   from    until   dur.  
======================|=========================|=========================
2019-01-01 early      | 08:00:00 16:00:00 8.00h | 15:55:00 16:00:00 0.08h
2019-01-01 late       | 16:00:00 00:00:00 8.00h | 16:00:00 16:15:00 0.25h

.net fiddle sample