You could try numpy.delete:
http://docs.scipy.org/doc/numpy/reference/generated/numpy.delete.html
or just get the slice of the array you want and write it to a new array.
For example:
a = np.random.randint(0,2, size=(48,366,3))
b = np.delete(a, np.s_[-1:], axis=1)
print b.shape # <--- (48,365,3)
or equivalently:
b = np.delete(a, -1, axis=1)
or:
b = a[:,:-1,:]