# [ACCEPTED]-How to Convert decimal number to time or vice versa-c#

When people talk about decimal hours, they 5 usually mean 0.1 = 6 minutes.

So, the correct 4 formula to convert 8.3 would be:

8 hours 3 + 3 * 6 minutes = 8:18

To convert 8:20 to 2 decimal it would be:

8 + 20/6 = 8.333333 1 (probably round to 8.3)

If it always be separated with **.** and you 4 want it for displaying then simply use this:

```
var ar="8.30".split(new[]{'.'});
Console.Write("{0} hours {1} minutes",ar[0], ar[1]);
```

PS: Here 3 we are sure to have two elements in array, but 2 please check length of array `ar`

before using 1 `ar[1]`

My approach would look something like this. (This 5 is ruby so you'll have to convert it yourself 4 but the logic is whats important here)

```
def zeropad(number)
return ((number.to_f < 10) ? "0" : "") + number.round.to_s
end
def decimal_to_time(value)
t = value.split(".") #returns an array of ["hour", "minutes"]
hours, minutes = t[0], t[1]
minutes = zeropad( (minutes.to_f / 10**minutes.length) * 60 ) # parse the minutes into a time value
return (minutes.to_i == 0) ? hours : hours + ":" + minutes
end
def findTime(value)
value =~ /^\d+\.\d+/ ? decimal_to_time(value) : value
end
```

Where 3 findTime("5.015") gives you the appropriate 2 time value.

I've tested this across the following 1 tests and they all pass.

```
| entered_time | expected_results|
| "5.6" | "5:36" |
| "5.9" | "5:54" |
| "5.09" | "5:05" |
| "5.0" | "5" |
| "5.00" | "5" |
| "5.015" | "5:01" |
| "6.03" | "6:02" |
| "5.30" | "5:18" |
| "4.2" | "4:12" |
| "8.3" | "8:18" |
| "8.33" | "8:20" |
| "105.5" | "105:30" |
| "16.7" | "16:42" |
| "Abc" | "Abc" |
| "5:36" | "5:36" |
| "5:44" | "5:44" |
```

Here's a couple of extension methods (for 5 DateTime and Decimal) that do the job:

```
public static class DecimalToTimeConverters
{
public static DateTime ToDateTime(this decimal value)
{
string[] parts = value.ToString().Split(new char[] { '.' });
int hours = Convert.ToInt32(parts[0]);
int minutes = Convert.ToInt32(parts[1]);
if ((hours > 23) || (hours < 0))
{
throw new ArgumentOutOfRangeException("value", "decimal value must be no greater than 23.59 and no less than 0");
}
if ((minutes > 59) || (minutes < 0))
{
throw new ArgumentOutOfRangeException("value", "decimal value must be no greater than 23.59 and no less than 0");
}
DateTime d = new DateTime(1, 1, 1, hours, minutes, 0);
return d;
}
public static Decimal ToDecimal(this DateTime datetime)
{
Decimal d = new decimal();
d = datetime.Hour;
d = d + Convert.ToDecimal((datetime.Minute * 0.01));
return d;
}
}
```

I 4 tested this very quickly in an ASP.net webpage 3 (I had a web project open at the time) using 2 the following in a new blank page, and it 1 seemed to work a treat:

```
protected void Page_Load(object sender, EventArgs e)
{
Response.Clear();
Decimal d = new decimal();
d = 3.45M;
Response.Write(d.ToDateTime().ToString());
Response.Write("<br />");
DateTime d2 = new DateTime(2009, 1, 1, 4, 55, 0);
Response.Write(d2.ToDecimal().ToString());
}
```

As per Rob but substitute

```
string[] parts = value.ToString().Split(new char[] { '.' });
int hours = Convert.ToInt32(parts[0]);
int minutes = Convert.ToInt32(parts[1]);
```

as

```
int hours = (int)value;
int minutes = (int)((value - minutes) * 100);
```

no strings 2 or reliance on current culture (the assumption 1 that the '.' is the decimal point)

How can I parse the `txtDuration.Text`

Value into a decimal 1 value?

```
if (txtDuration.Text)
{
var duration = int.Parse(txtDuration.Text);
var timespan = Boolean.Parse(hdfToggleDuration.Value) ? new TimeSpan (0, 0, duration, 0) : new TimeSpan (0, duration, 0, 0);
DateTime end = start.Add(timespan);
}
```

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