fix for issue 215

Author: jswhit

Changelog

@@ -1,5 +1,8 @@
  since version 1.0.8
  ===================
+
+ * fix for date2index error when time variable has only one entry (issue 215).
+
  * silence warnings ("Non-trivial type declarators in shared declaration (e.g.
    mix of pointers and values). Each pointer declaration should be on its own
    line") with Cython 0.2.

netcdftime.py

@@ -1101,8 +1101,12 @@ def time2index(times, nctime, calendar=None, select='exact'):
 
     # Trying to infer the correct index from the starting time and the stride.
     # This assumes that the times are increasing uniformly.
-    t0, t1 = nctime[:2]
-    dt = t1 - t0
+    if len(nctime) >= 2:
+        t0, t1 = nctime[:2]
+        dt = t1 - t0
+    else: 
+        t0 = nctime[0]
+        dt = 1.
     if select in ['exact', 'before']:
         index = numpy.array((num-t0)/dt, int)
     elif select == 'after':