Compute time between 2 dates

# Calculate the number of days between two dates entered from keyboard
from datetime import date

def getdate(stra):
    while True:
        s1 = input("Enter " + stra + " date as yyyy-mm-dd: ")
        ymd = makedate(s1)      # validate the input string, and make a date tuple
        if ymd:
            return ymd
        print("Invalid format, try again")

def makedate(inp):
    splitd = inp.split('-')     # Split string on hyphens
    if len(splitd) != 3:                # there should be 3 sections
        return None
    # check each section is numeric (more validation could be done here!!)
    if splitd[0].isdigit() and splitd[1].isdigit() and splitd[2].isdigit():
    # extract the year, month, and day
        y = int(splitd[0])
        m = int(splitd[1])
        d = int(splitd[2])
        return y,m,d
    return None

s1 = getdate("first")
s2 = getdate("second")
res1 = makedate(s1)
res2 = makedate(s2)

d1 = date(res1[0], res1[1], res1[2])
d2 = date(res2[0], res2[1], res2[2])
delta = d2 - d1
print(delta.days)