import numpy as np
import pandas as pd
from matplotlib.dates import date2num, YearLocator, DateFormatter
import datetime
from mpl_toolkits.basemap import Basemap
import matplotlib.pyplot as plt


map = Basemap(projection='ortho',
              lat_0=30, lon_0=10)

map.drawmapboundary(fill_color='aqua')
map.fillcontinents(color='coral',lake_color='aqua', alpha=0.3)
map.drawcoastlines()

x = np.random.randint(low=2, high=30, size=110)
y = np.random.randint(low=30, high=59, size=110)
x, y = map(x, y)
dates = pd.date_range(start="1900-01-01", end="2010-01-01", freq="A")

df = pd.DataFrame({"x": x, "y": y, "dates": dates})
dates = df.dates.apply(lambda x: x.strftime("%Y"))

years = YearLocator()
year_fmt = DateFormatter("%Y")
datemin = datetime.date(df["dates"].min().year, 1, 1)
datemax = datetime.date(df["dates"].max().year, 1, 1)

c  = [date2num(i) for i in df["dates"]]
print c
sc = map.scatter(df["x"], df["y"],50, marker="o", lw=.25,
                 c=c, cmap=plt.cm.viridis,
                 edgecolor='w',
                 alpha=0.9, antialiased=True,
                 label='Business Locations')

cbar = plt.colorbar(sc, ticks=YearLocator(5), format=DateFormatter("%Y"))


plt.show()