Reading PT0S to 0 second using C#

I have an XML file giving me the value PT0S.

 <Property name="TargetQuantity" type="double">
        <Value>PT0S</Value>
 </Property>

I have to store this value in a DATABASE table field – which is of type decimal. I have no idea how to convert this value to decimal. I am using C# to process this value.
I tried to use

Convert.ToDecimal

But it does not work.
Any advices would be helpful.

>Solution :

You can’t directly convert a timespan to a decimal. You need to decide which property you want.

See How do I convert an ISO8601 TimeSpan to a C# TimeSpan? (XmlConvert.ToTimeSpan(string)), and then for example save TimeSpan.TotalSeconds in your decimal column.