Hi Brandyn,

It would help if you would post code. But . . . NDSolve returns a rule which can be used to define a solution. NDSolveValue returns the solution itself. In both cases the solution is an interpolating function. It may be that the "value" you are seeing is the range limits that are displayed in the representation of the interpolating function. But the function itself accepts values of the independent variable, with the solution "valid" within the displayed range.You can see this if you execute the code below. (I deleted the output before posting because it would be very messy.)

Kind regards, David

eq = {y''[t] == -1, y[0] == 0, y'[0] == 10};

(* NDSolve returns a rule -- use it to define solution variable *)
solution = y /. NDSolve[eq, y, {t, 0, 20}][[1]]

Plot[solution[t], {t, 0, 20}]

(* NDSolveValue returns a solution -- set variable to it *)
solution = NDSolveValue[eq, y, {t, 0, 20}]

Plot[solution[t], {t, 0, 20}]