How to tell if a date is between two other dates?

Question

I have the following codes:

if date in (start, end):
        print('in between')
else:
        print('No!')

date, start and end are all variables with the format of 1/1. What should I do to have it print out the right result? i tried date as 10/2, start as 3/14 and end as 11/7 and it's print 'No!', which means it's not running right. I guess have to format them to a date format and then compare them.

What else have you tried? Since that doesn't work, what other code do you think might work? Have you read about `<` and `>` in a tutorial yet? — S.Lott, Mar 28 '11 at 20:03
i used start < date < end as well, and tried to use: from datetime import date. But it is still running wrong. this thing is that i just want to compare them in the month/date format since i have them in the same year. do i have to get the month and date out of month/date separately and then format them all together to compare? — widget, Mar 28 '11 at 20:23
@widget: "still running wrong"? Please provide an actual example of what you mean by "running wrong". "do i have to get the month and date out of month/date separately". No. — S.Lott, Mar 28 '11 at 20:36
Check the code in my answer. I tested it on both Python2.7 and Python3.1 and it works. — Maciej Ziarko, Mar 28 '11 at 20:44
@S.Lott: in this case i have it running correctly: from datetime import date d1 = date(2010, 3, 14) d2 = date(2010, 10, 2) d3 = date(2010, 11, 7) if d2 < d1 < d3: print 'Yes!' else: print 'Wrong!' The thing is that i have to get records of year, month, date and put them in d1, d2, d3 — widget, Mar 28 '11 at 20:50
@widget. Are you asking how to build `datetime` objects from "records"? That seems to be a new and different question. Step 1. Search for "datetime parsing". Step 2. Read the `datetime` library in the Python docs. Step 3. If you cannot find anything then ask a separate question. — S.Lott, Mar 28 '11 at 20:52
related: [Python - Working out if time now is between two times](http://stackoverflow.com/q/20518122/4279) — jfs, Dec 10 '15 at 23:19

score 143 · Answer 1 · edited Jun 26 '21 at 02:13

143

If you convert all your dates to datetime.date, you can write the following:

if start <= date <= end:
    print("in between")
else:
    print("No!")

edited Jun 26 '21 at 02:13

Shedrack

656
7
22

answered Mar 28 '11 at 20:05

Björn Pollex

75,346
28
201
283

An example for the `start` var is `import datetime; start=datetime.date(2023,1,7)` – Timo Jan 07 '23 at 11:05

Maciej Ziarko · Accepted Answer · 2011-03-28T21:01:27.273

55

As you are still not satisfied, I have another answer for you. Without using datetime and year.

It just uses built-in tuples and comparing them:

d1 = (3, 28)
d2 = (3, 31)
d3 = (4, 2)
if d1 < d2 < d3:
    print("BETWEEN!")
else:
    print("NOT!")

You can create tuple like these easily:

day = 16
month = 4
d = (month, day)

edited Mar 28 '11 at 21:01

answered Mar 28 '11 at 20:56

Maciej Ziarko

11,494
13
48
69

I think this is exactly what i want. i have them converted to int and add to tuple. it works very well! Thank u so much! – widget Mar 28 '11 at 21:12
Just remember that doing it this way, you can't be sure if they are real dates. But if you're dealing with only real dates, it is probably the most efficient and easiest way. – Maciej Ziarko Mar 28 '11 at 21:18
I got the date data from my table. so they are real dates. yeah i like this comparing method, it's efficient – widget Mar 29 '11 at 17:09
2

Note that it can be used only for dates of one year! – Demian Wolf May 29 '20 at 19:40

score 39 · Answer 3 · edited Jun 28 '21 at 23:17

39

Use datetime.date:

http://docs.python.org/library/datetime.html#datetime.date

< operator is overloaded specially for you.

date1 < date2 - date1 is considered less than date2 when date1 precedes date2 in time.

>>> from datetime import date
>>> d1 = date(2011, 3, 28)
>>> d2 = date(2011, 3, 22)
>>> d3 = date(2011, 4, 3)
>>> d2 < d1 < d3
True

Or in your prgram:

from datetime import date

d1 = date(2011, 3, 28)
d2 = date(2011, 3, 22)
d3 = date(2011, 4, 3)

if d2 < d1 < d3:
    print('in between')
else:
    print('No!')

edited Jun 28 '21 at 23:17

Shedrack

656
7
22

answered Mar 28 '11 at 20:05

Maciej Ziarko

11,494
13
48
69

your codes seem right to me. now i guess i would have to get records of year, month and date separately.i didnot think it is necessary though – widget Mar 28 '11 at 20:52
1

I will write for you answer without year and without datetime. Just gime me 2 minutes. – Maciej Ziarko Mar 28 '11 at 20:53
I wrote another answer. Check it! – Maciej Ziarko Mar 28 '11 at 20:56

score 3 · Answer 4 · edited Jun 27 '21 at 14:17

from datetime import datetime

date_format = "%m/%d/%Y"

a = datetime.strptime('8/18/2008', date_format)

b = datetime.strptime('9/26/2007', date_format) # Date to be checked

c = datetime.strptime('9/25/2008', date_format)

d = datetime.strptime('8/18/2008', date_format)  #Date entered here should always be the same as 'a'

delta1 = b - a

delta2 = c - b

delta3 = d - a

if delta1.days >= delta3.days and delta2.days >= delta3.days:

    print('In between')

else:

    print('Not in between')

How to tell if a date is between two other dates?

4 Answers4

Linked