300
votes

I have to create an "Expires" value 5 minutes in the future, but I have to supply it in UNIX Timestamp format. I have this so far, but it seems like a hack.

def expires():
    '''return a UNIX style timestamp representing 5 minutes from now'''
    epoch = datetime.datetime(1970, 1, 1)
    seconds_in_a_day = 60 * 60 * 24
    five_minutes = datetime.timedelta(seconds=5*60)
    five_minutes_from_now = datetime.datetime.now() + five_minutes
    since_epoch = five_minutes_from_now - epoch
    return since_epoch.days * seconds_in_a_day + since_epoch.seconds

Is there a module or function that does the timestamp conversion for me?

11
I recommend changing the subject of this question. The question is good, but it is not about converting datetime to Unix timestamp. It is about how to get a Unix timestamp 5 minutes in the future. - D. A.
I disagree, @D.A. The question essentially says "I need to do X and Y. Here's what I have now. What's a better way to do Y?" Maybe there are better ways to do X, but the title and the body clearly ask about Y. - Rob Kennedy
I agree with you completely on the question, and I think it a good one with a good answer. The problem is "Python datetime to Unix timestamp" doesn't reflect either the question or answer. I found this post searching for a way to do the conversion, and I lost time because of the misleading subject line. I suggest: "Python, 5 minutes in the future as UNIX Timestamp" - D. A.
@JimmyKane - A pretty comprehensive answer on how to get a timestamp from a date time can be found here: stackoverflow.com/questions/8777753/… - Tim Tisdall
@TimTisdall yes since the title is changed it makes no sense - Jimmy Kane

11 Answers

353
votes

Another way is to use calendar.timegm:

future = datetime.datetime.utcnow() + datetime.timedelta(minutes=5)
return calendar.timegm(future.timetuple())

It's also more portable than %s flag to strftime (which doesn't work on Windows).

157
votes

Now in Python >= 3.3 you can just call the timestamp() method to get the timestamp as a float.

import datetime
current_time = datetime.datetime.now(datetime.timezone.utc)
unix_timestamp = current_time.timestamp() # works if Python >= 3.3

unix_timestamp_plus_5_min = unix_timestamp + (5 * 60)  # 5 min * 60 seconds
142
votes

Just found this, and its even shorter.

import time
def expires():
    '''return a UNIX style timestamp representing 5 minutes from now'''
    return int(time.time()+300)
57
votes

This is what you need:

import time
import datetime
n = datetime.datetime.now()
unix_time = time.mktime(n.timetuple())
48
votes

You can use datetime.strftime to get the time in Epoch form, using the %s format string:

def expires():
    future = datetime.datetime.now() + datetime.timedelta(seconds=5*60)
    return int(future.strftime("%s"))

Note: This only works under linux, and this method doesn't work with timezones.

11
votes

Here's a less broken datetime-based solution to convert from datetime object to posix timestamp:

future = datetime.datetime.utcnow() + datetime.timedelta(minutes=5)
return (future - datetime.datetime(1970, 1, 1)).total_seconds()

See more details at Converting datetime.date to UTC timestamp in Python.

6
votes
def in_unix(input):
  start = datetime.datetime(year=1970,month=1,day=1)
  diff = input - start
  return diff.total_seconds()
4
votes

The key is to ensure all the dates you are using are in the utc timezone before you start converting. See http://pytz.sourceforge.net/ to learn how to do that properly. By normalizing to utc, you eliminate the ambiguity of daylight savings transitions. Then you can safely use timedelta to calculate distance from the unix epoch, and then convert to seconds or milliseconds.

Note that the resulting unix timestamp is itself in the UTC timezone. If you wish to see the timestamp in a localized timezone, you will need to make another conversion.

Also note that this will only work for dates after 1970.

   import datetime
   import pytz

   UNIX_EPOCH = datetime.datetime(1970, 1, 1, 0, 0, tzinfo = pytz.utc)
   def EPOCH(utc_datetime):
      delta = utc_datetime - UNIX_EPOCH
      seconds = delta.total_seconds()
      ms = seconds * 1000
      return ms
4
votes

The following is based on the answers above (plus a correction for the milliseconds) and emulates datetime.timestamp() for Python 3 before 3.3 when timezones are used.

def datetime_timestamp(datetime):
    '''
    Equivalent to datetime.timestamp() for pre-3.3
    '''
    try:
        return datetime.timestamp()
    except AttributeError:
        utc_datetime = datetime.astimezone(utc)
        return timegm(utc_datetime.timetuple()) + utc_datetime.microsecond / 1e6

To strictly answer the question as asked, you'd want:

datetime_timestamp(my_datetime) + 5 * 60

datetime_timestamp is part of simple-date. But if you were using that package you'd probably type:

SimpleDate(my_datetime).timestamp + 5 * 60

which handles many more formats / types for my_datetime.

1
votes
def expiration_time():
    import datetime,calendar
    timestamp = calendar.timegm(datetime.datetime.now().timetuple())
    returnValue = datetime.timedelta(minutes=5).total_seconds() + timestamp
    return returnValue
1
votes

Note that solutions with timedelta.total_seconds() work on python-2.7+. Use calendar.timegm(future.utctimetuple()) for lower versions of Python.