Converting datetime date to UTC timestamp in Python

Question

I am dealing with dates in Python and I need to convert them to UTC timestamps to be used inside Javascript  The following code does not work    gt  gt  gt  d   datetime date 2011 01 01   gt  gt  gt  datetime datetime utcfromtimestamp time mktime d timetuple     datetime datetime 2010  12  31  23  0    Converting the date object first to datetime also does not help  I tried the example at this link from  but   from pytz import utc  timezone from datetime import datetime from time import mktime input date   datetime year 2011  month 1  day 15    and now either   mktime utc localize input date  utctimetuple      or  mktime timezone  US Eastern   localize input date  utctimetuple      does work   So general question  how can I get a date converted to seconds since epoch according to UTC

User · Answer

i m impressed of the deep discussion   my 2 cents   from datetime import datetime import time  the timestamp in utc is   timestamp      datetime utcnow   - datetime 1970 1 1   total seconds     or    timestamp   time time     if now results from datetime now    in the same DST  utcoffset    datetime now   - datetime utcnow    total seconds   timestamp      now - datetime 1970 1 1   total seconds   - utcoffset

User · Answer

For unix systems only    gt  gt  gt  import datetime  gt  gt  gt  d   datetime date 2011 01 01   gt  gt  gt  d strftime   s       lt -- THIS IS THE CODE YOU WANT  1293832800    Note 1  dizzyf observed that this applies localized timezones  Don t use in production   Note 2  Jakub Narebski noted that this ignores timezone information even for offset-aware datetime  tested for Python 2 7

User · Answer

follow the python2 7 document  you have to use calendar timegm   instead of time mktime     gt  gt  gt  d   datetime date 2011 01 01   gt  gt  gt  datetime datetime utcfromtimestamp calendar timegm d timetuple     datetime datetime 2011  1  1  0  0

User · Answer

I defined my own two functions   utc time2datetime utc time  tz None  datetime2utc time datetime    here   import time import datetime from pytz import timezone import calendar import pytz   def utc time2datetime utc time  tz None         convert utc time to utc datetime     utc datetime   datetime datetime fromtimestamp utc time         add time zone to utc datetime     if tz is None          tz datetime   utc datetime astimezone timezone  utc        else          tz datetime   utc datetime astimezone tz       return tz datetime   def datetime2utc time datetime         add utc time zone if no time zone is set     if datetime tzinfo is None          datetime   datetime replace tzinfo timezone  utc           convert to utc time zone from whatever time zone the datetime is set to     utc datetime   datetime astimezone timezone  utc    replace tzinfo None         create a time tuple from datetime     utc timetuple   utc datetime timetuple          create a time element from the tuple an add microseconds     utc time   calendar timegm utc timetuple    datetime microsecond   1E6      return utc time

User · Answer

If d   date 2011  1  1  is in UTC    gt  gt  gt  from datetime import datetime  date  gt  gt  gt  import calendar  gt  gt  gt  timestamp1   calendar timegm d timetuple     gt  gt  gt  datetime utcfromtimestamp timestamp1  datetime datetime 2011  1  1  0  0    If d is in local timezone    gt  gt  gt  import time  gt  gt  gt  timestamp2   time mktime d timetuple      DO NOT USE IT WITH UTC DATE  gt  gt  gt  datetime fromtimestamp timestamp2  datetime datetime 2011  1  1  0  0    timestamp1 and timestamp2 may differ if midnight in the local timezone is not the same time instance as midnight in UTC   mktime   may return a wrong result if d corresponds to an ambiguous local time  e g   during DST transition  or if d is a past future  date when the utc offset might have been different and the C mktime   has no access to the tz database on the given platform  You could use pytz module  e g   via tzlocal get localzone    to get access to the tz database on all platforms  Also  utcfromtimestamp   may fail and mktime   may return non-POSIX timestamp if  right  timezone is used     To convert datetime date object that represents date in UTC without calendar timegm     DAY   24 60 60   POSIX day in seconds  exact value  timestamp    utc date toordinal   - date 1970  1  1  toordinal      DAY timestamp    utc date - date 1970  1  1   days   DAY   How can I get a date converted to seconds since epoch according to UTC   To convert datetime datetime  not datetime date  object that already represents time in UTC to the corresponding POSIX timestamp  a float    Python 3 3   datetime timestamp     from datetime import timezone  timestamp   dt replace tzinfo timezone utc  timestamp     Note  It is necessary to supply timezone utc explicitly otherwise  timestamp   assume that your naive datetime object is in local timezone   Python 3   lt  3 3   From the docs for datetime utcfromtimestamp        There is no method to obtain the timestamp from a datetime instance    but POSIX timestamp corresponding to a datetime instance dt can be   easily calculated as follows  For a naive dt    timestamp    dt - datetime 1970  1  1     timedelta seconds 1       And for an aware dt    timestamp    dt - datetime 1970 1 1  tzinfo timezone utc     timedelta seconds 1    Interesting read  Epoch time vs  time of day on the difference between What time is it  and How many seconds have elapsed   See also  datetime needs an  epoch  method  Python 2  To adapt the above code for Python 2   timestamp    dt - datetime 1970  1  1   total seconds     where timedelta total seconds   is equivalent to  td microseconds    td seconds   td days   24   3600    10  6    10  6 computed with true division enabled   Example  from   future   import division from datetime import datetime  timedelta  def totimestamp dt  epoch datetime 1970 1 1        td   dt - epoch       return td total seconds       return  td microseconds    td seconds   td days   86400    10  6    10  6   now   datetime utcnow   print now print totimestamp now    Beware of floating-point issues   Output  2012-01-08 15 34 10 022403 1326036850 02   How to convert an aware datetime object to POSIX timestamp  assert dt tzinfo is not None and dt utcoffset   is not None timestamp   dt timestamp     Python 3 3    On Python 3   from datetime import datetime  timedelta  timezone  epoch   datetime 1970  1  1  tzinfo timezone utc  timestamp    dt - epoch    timedelta seconds 1  integer timestamp    dt - epoch     timedelta seconds 1    On Python 2     utc time   local time              - utc offset utc naive    dt replace tzinfo None  - dt utcoffset   timestamp    utc naive - datetime 1970  1  1   total seconds

User · Answer

A complete time-string contains    date time utcoffset   HHMM or -HHMM    For example   1970-01-01 06 00 00  0500    1970-01-01 01 00 00  0000    UNIX timestamp 3600    python3  gt  gt  gt  from datetime import datetime  gt  gt  gt  from calendar import timegm  gt  gt  gt  tm    1970-01-01 06 00 00  0500   gt  gt  gt  fmt     Y- m- d  H  M  S  z   gt  gt  gt  timegm datetime strptime tm  fmt  utctimetuple    3600   Note        UNIX timestamp is a floating point number expressed in seconds since the epoch  in UTC      Edit     python3  gt  gt  gt  from datetime import datetime  timezone  timedelta  gt  gt  gt  from calendar import timegm  gt  gt  gt  dt   datetime 1970  1  1  6  0   gt  gt  gt  tz   timezone timedelta hours 5    gt  gt  gt  timegm dt replace tzinfo tz  utctimetuple    3600

User · Answer

Using the arrow package    gt  gt  gt  import arrow  gt  gt  gt  arrow get 2010  12  31  timestamp 1293753600  gt  gt  gt  time gmtime 1293753600  time struct time tm year 2010  tm mon 12  tm mday 31       tm hour 0  tm min 0  tm sec 0       tm wday 4  tm yday 365  tm isdst 0

User · Answer

the question is a little confused   timestamps are not UTC - they re a Unix thing   the date might be UTC   assuming it is  and if you re using Python 3 2   simple-date makes this trivial    gt  gt  gt  SimpleDate date 2011 1 1   tz  utc   timestamp 1293840000 0   if you actually have the year  month and day you don t need to create the date    gt  gt  gt  SimpleDate 2011 1 1  tz  utc   timestamp 1293840000 0   and if the date is in some other timezone  this matters because we re assuming midnight without an associated time     gt  gt  gt  SimpleDate date 2011 1 1   tz  America New York   timestamp 1293858000 0    the idea behind simple-date is to collect all python s date and time stuff in one consistent class  so you can do any conversion   so  for example  it will also go the other way    gt  gt  gt  SimpleDate 1293858000  tz  utc   date datetime date 2011  1  1

User · Answer

Considering you have a datetime object called d  use the following to get the timestamp in UTC   d strftime   Y- m- dT H  M  S  fZ     And for the opposite direction  use following    d   datetime strptime  2008-09-03T20 56 35 450686Z     Y- m- dT H  M  S  fZ

User · Answer

Assumption 1  You re attempting to convert a date to a timestamp  however since a date covers a 24 hour period  there isn t a single timestamp that represents that date  I ll assume that you want to represent the timestamp of that date at midnight  00 00 00 000   Assumption 2  The date you present is not associated with a particular time zone  however you want to determine the offset from a particular time zone  UTC   Without knowing the time zone the date is in  it isn t possible to calculate a timestamp for a specific time zone  I ll assume that you want to treat the date as if it is in the local system time zone    First  you can convert the date instance into a tuple representing the various time components using the timetuple   member   dtt   d timetuple     time struct time tm year 2011  tm mon 1  tm mday 1  tm hour 0  tm min 0  tm sec 0  tm wday 5  tm yday 1  tm isdst -1    You can then convert that into a timestamp using time mktime   ts   time mktime dtt    1293868800 0   You can verify this method by testing it with the epoch time itself  1970-01-01   in which case the function should return the timezone offset for the local time zone on that date   d   datetime date 1970 1 1  dtt   d timetuple     time struct time tm year 1970  tm mon 1  tm mday 1  tm hour 0  tm min 0  tm sec 0  tm wday 3  tm yday 1  tm isdst -1  ts   time mktime dtt    28800 0   28800 0 is 8 hours  which would be correct for the Pacific time zone  where I m at

[python] Converting datetime.date to UTC timestamp in Python

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