Before Matplotlib 3.3, the epoch was 0000-12-31, later it changes to …

…1970-01-01 UTC

Evaluate/interpolateTracks.py

@@ -3,7 +3,7 @@
 import numpy as np
 
 from datetime import datetime, timedelta
-from matplotlib.dates import num2date
+from matplotlib.dates import num2date, date2num
 from scipy.interpolate import interp1d, splev, splrep
 
 from Utilities.maputils import latLon2Azi
@@ -95,7 +95,7 @@ def interpolate(track, delta, interpolation_type=None):
 
     newtime = np.arange(timestep[0], timestep[-1] + .01, delta)
     newtime[-1] = timestep[-1]
-    _newtime = (newtime / 24.) + time_[0]
+    _newtime = (newtime / 24.) + time_[0] + date2num(np.datetime64('0000-12-31'))     #  Before Matplotlib 3.3, the epoch was 0000-12-31, later it changes to 1970-01-01 UTC 
     newdates = num2date(_newtime)
     newdates = np.array([n.replace(tzinfo=None) for n in newdates])