from datetime import datetime


def days_between(d1, d2):
    """Calculate the number of days between two dates.  D1 is start date (inclusive) and d2 is end date (inclusive)"""
    d1 = datetime.strptime(d1, "%Y-%m-%d")
    d2 = datetime.strptime(d2, "%Y-%m-%d")
    return abs((d2 - d1).days + 1)