How SetValue to TimeSpan Property with Reflection c#?

I have the following problem:

I'm trying to Set a value of a TimeSpan property with reflection but the property reflect as Int64 Ticks with SetMethod null and when I try to make (PropertyInfo).SetValue(...,...) I get a "property set method not found" Exception.

So my question is:

How Can I Set a TimeSpan value of a property by Reflection?

I'm using following code that works for all properties with exception of TimeSpan

private static void PropSetValue(PropertyInfo prop, PropertyInfo updaterProp, object updater, object toUpdate)
{
    var propValue = prop.GetValue(toUpdate, null);
    var updValue = updaterProp.GetValue(updater, null);

    if (!Equals(propValue, updValue))
        prop.SetValue(toUpdate, updValue, null);
}

Thankyou in advance for suggestions or workarounds.

Piercarlo