C/C++ :: Error C2064 / Term Does Not Evaluate To A Function Taking 1 Arguments

i'm implementing a templated function callback.

I get this error:

"error C2064: term does not evaluate to a function taking 1 arguments"

I'm not sure why.

Here's the code for the template function in the timer class header:

template<class T>
void TimerEvent(DateAndTime DateTime, std::function<void(T)> Callback);

Now the class body:

template<class T>
void GameTimer::TimerEvent(DateAndTime DateTime, std::function<void(T)> Callback)
{
DateAndTime time;
time.Now(false);
if (time.Compare(DateTime) == 1)
Callback(T);
}

and calling the class in the Engine:

int test1(int a)
{
}
void Main()
{
gameTime.TimerEvent<int>(gh, test1(1));
}