diff --git a/fitter.py b/fitter.py
index 17b3832..226d59f 100644
--- a/fitter.py
+++ b/fitter.py
@@ -22,7 +22,7 @@ class Fitter:
         self.current_fit_range = current_fit_range
         self.fit_results = {}
 
-        self.tspan = [0, 1000]
+        self.tspan = self.time_points
         self.dt: float = 1  # 1.0
         self.time_points = np.arange(*self.tspan, self.dt)