How do I calculate the date six months from the cu

Question

I am using the datetime Python module. I am looking to calculate the date 6 months from the current date. Could someone give me a little help doing this?

The reason I want to generate a date 6 months from the current date is to produce a Review Date. If the user enters data into the system it will have a review date of 6 months from the date they entered the data.

Answer 1

What do you mean by '6 months'. Is 2009-02-13 + 6 months == 2009-08-13 or is it 2009-02-13 + 6*30 days?

import mx.DateTime as dt

#6 Months
dt.now()+dt.RelativeDateTime(months=6)
#result is '2009-08-13 16:28:00.84'

#6*30 days
dt.now()+dt.RelativeDateTime(days=30*6)
#result is '2009-08-12 16:30:03.35'

More info about mx.DateTime

Answer 2

The QDate class of PyQt4 has an addmonths function.

>>>from PyQt4.QtCore import QDate  
>>>dt = QDate(2009,12,31)  
>>>required = dt.addMonths(6) 

>>>required
PyQt4.QtCore.QDate(2010, 6, 30)

>>>required.toPyDate()
datetime.date(2010, 6, 30)

Answer 3

import time

def add_month(start_time, months):  

        ret = time.strptime(start_time, '%Y-%m-%d')
        t = list(ret)

        t[1] += months

        if t[1] > 12:
            t[0] += 1 + int(months / 12)

            t[1] %= 12

        return int(time.mktime(tuple(t)))

Answer 4

I solved this problem like this:

import calendar
from datetime import datetime
moths2add = 6
now = datetime.now()
current_year = now.year
current_month = now.month
#count days in months you want to add using calendar module
days = sum(
  [calendar.monthrange(current_year, elem)[1] for elem in range(current_month, current_month + moths)]
    )
print now + days

Answer 5

given that your datetime variable is called date:

date=datetime.datetime(year=date.year+int((date.month+6)/12),
                       month=(date.month+6)%13 + (1 if (date.month + 
                       months>12) else 0), day=date.day)

Answer 6

Yet another solution - hope someone will like it:

def add_months(d, months):
    return d.replace(year=d.year+months//12).replace(month=(d.month+months)%12)

This solution doesn't work for days 29,30,31 for all cases, so more robust solution is needed (which is not so nice anymore :) ):

def add_months(d, months):
    for i in range(4):
        day = d.day - i
        try:
            return d.replace(day=day).replace(year=d.year+int(months)//12).replace(month=(d.month+int(months))%12)
        except:
            pass
    raise Exception("should not happen")