blocks|key|986740|text|date+=+datetime.datetime(2003,8,1,12,4,5)
for+i+in+range(5):+
++++date+%2B=+datetime.timedelta(days=1)
++++print(date)+|type|code-block|depth|inlineStyleRanges|entityRanges|data|syntax|javascript|986741|unstyled|entityMap^0|0^^$0|@$1|2|3|4|5|6|7|G|8|@]|9|@]|A|$B|C]]|$1|D|3|-4|5|E|7|H|8|@]|9|@]|A|$]]]|F|$]]

<pre><code>date = datetime.datetime(2003,8,1,12,4,5)
for i in range(5): 
    date += datetime.timedelta(days=1)
    print(date) 
</code></pre>


blocks|key|1201311|text|递增日期可以使用timedelta对象来完成：|type|unstyled|depth|inlineStyleRanges|entityRanges|data|1201312|import+datetime

datetime.datetime.now()+%2B+datetime.timedelta(days=1)|code-block|syntax|javascript|1201313|在Python文档中查找timedelta对象：http://docs.python.org/library/datetime.html|offset|length|1201314|entityMap|0|LINK|mutability|MUTABLE|url|http://docs.python.org/library/datetime.html^0|0|0|O|18|0|0^^$0|@$1|2|3|4|5|6|7|S|8|@]|9|@]|A|$]]|$1|B|3|C|5|D|7|T|8|@]|9|@]|A|$E|F]]|$1|G|3|H|5|6|7|U|8|@]|9|@$I|V|J|W|1|X]]|A|$]]|$1|K|3|-4|5|6|7|Y|8|@]|9|@]|A|$]]]|L|$M|$5|N|O|P|A|$Q|R]]]]

<p>Incrementing dates can be accomplished using timedelta objects:</p>

<pre><code>import datetime

datetime.datetime.now() + datetime.timedelta(days=1)
</code></pre>

<p>Look up timedelta objects in the Python docs: <a href="http://docs.python.org/library/datetime.html" rel="noreferrer">http://docs.python.org/library/datetime.html</a></p>


blocks|key|1201435|text|当前的所有答案在某些情况下都是错误的，因为它们没有考虑时区相对于UTC的偏移量。因此，在某些情况下，添加24小时与添加日历日不同。|type|unstyled|depth|inlineStyleRanges|entityRanges|data|1201436|建议的解决方案|1201437|以下解决方案适用于萨摩亚，并保持本地时间恒定。|1201438|def+add_day(today):
++++"""
++++Add+a+day+to+the+current+day.

++++This+takes+care+of+historic+offset+changes+and+DST.

++++Parameters
++++----------
++++today+:+timezone-aware+datetime+object

++++Returns
++++-------
++++tomorrow+:+timezone-aware+datetime+object
++++"""
++++today_utc+=+today.astimezone(datetime.timezone.utc)
++++tz+=+today.tzinfo
++++tomorrow_utc+=+today_utc+%2B+datetime.timedelta(days=1)
++++tomorrow_utc_tz+=+tomorrow_utc.astimezone(tz)
++++tomorrow_utc_tz+=+tomorrow_utc_tz.replace(hour=today.hour,
++++++++++++++++++++++++++++++++++++++++++++++minute=today.minute,
++++++++++++++++++++++++++++++++++++++++++++++second=today.second)
++++return+tomorrow_utc_tz|code-block|syntax|javascript|1201439|测试代码|1201440|#+core+modules
import+datetime

#+3rd+party+modules
import+pytz


#+add_day+methods
def+add_day(today):
++++"""
++++Add+a+day+to+the+current+day.

++++This+takes+care+of+historic+offset+changes+and+DST.

++++Parameters
++++----------
++++today+:+timezone-aware+datetime+object

++++Returns
++++-------
++++tomorrow+:+timezone-aware+datetime+object
++++"""
++++today_utc+=+today.astimezone(datetime.timezone.utc)
++++tz+=+today.tzinfo
++++tomorrow_utc+=+today_utc+%2B+datetime.timedelta(days=1)
++++tomorrow_utc_tz+=+tomorrow_utc.astimezone(tz)
++++tomorrow_utc_tz+=+tomorrow_utc_tz.replace(hour=today.hour,
++++++++++++++++++++++++++++++++++++++++++++++minute=today.minute,
++++++++++++++++++++++++++++++++++++++++++++++second=today.second)
++++return+tomorrow_utc_tz


def+add_day_datetime_timedelta_conversion(today):
++++#+Correct+for+Samoa,+but+dst+shift
++++today_utc+=+today.astimezone(datetime.timezone.utc)
++++tz+=+today.tzinfo
++++tomorrow_utc+=+today_utc+%2B+datetime.timedelta(days=1)
++++tomorrow_utc_tz+=+tomorrow_utc.astimezone(tz)
++++return+tomorrow_utc_tz


def+add_day_dateutil_relativedelta(today):
++++#+WRONG!
++++from+dateutil.relativedelta+import+relativedelta
++++return+today+%2B+relativedelta(days=1)


def+add_day_datetime_timedelta(today):
++++#+WRONG!
++++return+today+%2B+datetime.timedelta(days=1)


#+Test+cases
def+test_samoa(add_day):
++++"""
++++Test+if+add_day+properly+increases+the+calendar+day+for+Samoa.

++++Due+to+economic+considerations,+Samoa+went+from+2011-12-30+10:00-11:00
++++to+2011-12-30+10:00%2B13:00.+Hence+the+country+skipped+2011-12-30+in+its
++++local+time.

++++See+https://stackoverflow.com/q/52084423/562769

++++A+common+wrong+result+here+is+2011-12-30T23:59:00-10:00.+This+date+never
++++happened+in+Samoa.
++++"""
++++tz+=+pytz.timezone('Pacific/Apia')
++++today_utc+=+datetime.datetime(2011,+12,+30,+9,+59,
++++++++++++++++++++++++++++++++++tzinfo=datetime.timezone.utc)
++++today_tz+=+today_utc.astimezone(tz)++#+2011-12-29T23:59:00-10:00
++++tomorrow+=+add_day(today_tz)
++++return+tomorrow.isoformat()+==+'2011-12-31T23:59:00%2B14:00'


def+test_dst(add_day):
++++"""Test+if+add_day+properly+increases+the+calendar+day+if+DST+happens."""
++++tz+=+pytz.timezone('Europe/Berlin')
++++today_utc+=+datetime.datetime(2018,+3,+25,+0,+59,
++++++++++++++++++++++++++++++++++tzinfo=datetime.timezone.utc)
++++today_tz+=+today_utc.astimezone(tz)++#+2018-03-25T01:59:00%2B01:00
++++tomorrow+=+add_day(today_tz)
++++return+tomorrow.isoformat()+==+'2018-03-26T01:59:00%2B02:00'


to_test+=+[(add_day_dateutil_relativedelta,+'relativedelta'),
+++++++++++(add_day_datetime_timedelta,+'timedelta'),
+++++++++++(add_day_datetime_timedelta_conversion,+'timedelta%2Bconversion'),
+++++++++++(add_day,+'timedelta%2Bconversion%2Bdst')]
print('{:<25}:+{:>5}+{:>5}'.format('Method',+'Samoa',+'DST'))
for+method,+name+in+to_test:
++++print('{:<25}:+{:>5}+{:>5}'
++++++++++.format(name,
++++++++++++++++++test_samoa(method),
++++++++++++++++++test_dst(method)))|1201441|测试结果|1201442|Method+++++++++++++++++++:+Samoa+++DST
relativedelta++++++++++++:+++++0+++++0
timedelta++++++++++++++++:+++++0+++++0
timedelta%2Bconversion+++++:+++++1+++++0
timedelta%2Bconversion%2Bdst+:+++++1+++++1|1201443|entityMap^0|0|0|0|0|0|0|0|0^^$0|@$1|2|3|4|5|6|7|U|8|@]|9|@]|A|$]]|$1|B|3|C|5|6|7|V|8|@]|9|@]|A|$]]|$1|D|3|E|5|6|7|W|8|@]|9|@]|A|$]]|$1|F|3|G|5|H|7|X|8|@]|9|@]|A|$I|J]]|$1|K|3|L|5|6|7|Y|8|@]|9|@]|A|$]]|$1|M|3|N|5|H|7|Z|8|@]|9|@]|A|$I|J]]|$1|O|3|P|5|6|7|10|8|@]|9|@]|A|$]]|$1|Q|3|R|5|H|7|11|8|@]|9|@]|A|$I|J]]|$1|S|3|-4|5|6|7|12|8|@]|9|@]|A|$]]]|T|$]]

<p>All of the current answers are wrong in some cases as they do not consider that timezones change their offset relative to UTC. So in some cases adding 24h is different from adding a calendar day.</p>

<h2>Proposed solution</h2>

<p>The following solution works for Samoa and keeps the local time constant.</p>

<pre><code>def add_day(today):
    """
    Add a day to the current day.

    This takes care of historic offset changes and DST.

    Parameters
    ----------
    today : timezone-aware datetime object

    Returns
    -------
    tomorrow : timezone-aware datetime object
    """
    today_utc = today.astimezone(datetime.timezone.utc)
    tz = today.tzinfo
    tomorrow_utc = today_utc + datetime.timedelta(days=1)
    tomorrow_utc_tz = tomorrow_utc.astimezone(tz)
    tomorrow_utc_tz = tomorrow_utc_tz.replace(hour=today.hour,
                                              minute=today.minute,
                                              second=today.second)
    return tomorrow_utc_tz
</code></pre>

<h2>Tested Code</h2>

<pre><code># core modules
import datetime

# 3rd party modules
import pytz


# add_day methods
def add_day(today):
    """
    Add a day to the current day.

    This takes care of historic offset changes and DST.

    Parameters
    ----------
    today : timezone-aware datetime object

    Returns
    -------
    tomorrow : timezone-aware datetime object
    """
    today_utc = today.astimezone(datetime.timezone.utc)
    tz = today.tzinfo
    tomorrow_utc = today_utc + datetime.timedelta(days=1)
    tomorrow_utc_tz = tomorrow_utc.astimezone(tz)
    tomorrow_utc_tz = tomorrow_utc_tz.replace(hour=today.hour,
                                              minute=today.minute,
                                              second=today.second)
    return tomorrow_utc_tz


def add_day_datetime_timedelta_conversion(today):
    # Correct for Samoa, but dst shift
    today_utc = today.astimezone(datetime.timezone.utc)
    tz = today.tzinfo
    tomorrow_utc = today_utc + datetime.timedelta(days=1)
    tomorrow_utc_tz = tomorrow_utc.astimezone(tz)
    return tomorrow_utc_tz


def add_day_dateutil_relativedelta(today):
    # WRONG!
    from dateutil.relativedelta import relativedelta
    return today + relativedelta(days=1)


def add_day_datetime_timedelta(today):
    # WRONG!
    return today + datetime.timedelta(days=1)


# Test cases
def test_samoa(add_day):
    """
    Test if add_day properly increases the calendar day for Samoa.

    Due to economic considerations, Samoa went from 2011-12-30 10:00-11:00
    to 2011-12-30 10:00+13:00. Hence the country skipped 2011-12-30 in its
    local time.

    See https://stackoverflow.com/q/52084423/562769

    A common wrong result here is 2011-12-30T23:59:00-10:00. This date never
    happened in Samoa.
    """
    tz = pytz.timezone('Pacific/Apia')
    today_utc = datetime.datetime(2011, 12, 30, 9, 59,
                                  tzinfo=datetime.timezone.utc)
    today_tz = today_utc.astimezone(tz)  # 2011-12-29T23:59:00-10:00
    tomorrow = add_day(today_tz)
    return tomorrow.isoformat() == '2011-12-31T23:59:00+14:00'


def test_dst(add_day):
    """Test if add_day properly increases the calendar day if DST happens."""
    tz = pytz.timezone('Europe/Berlin')
    today_utc = datetime.datetime(2018, 3, 25, 0, 59,
                                  tzinfo=datetime.timezone.utc)
    today_tz = today_utc.astimezone(tz)  # 2018-03-25T01:59:00+01:00
    tomorrow = add_day(today_tz)
    return tomorrow.isoformat() == '2018-03-26T01:59:00+02:00'


to_test = [(add_day_dateutil_relativedelta, 'relativedelta'),
           (add_day_datetime_timedelta, 'timedelta'),
           (add_day_datetime_timedelta_conversion, 'timedelta+conversion'),
           (add_day, 'timedelta+conversion+dst')]
print('{:&lt;25}: {:&gt;5} {:&gt;5}'.format('Method', 'Samoa', 'DST'))
for method, name in to_test:
    print('{:&lt;25}: {:&gt;5} {:&gt;5}'
          .format(name,
                  test_samoa(method),
                  test_dst(method)))
</code></pre>

<h2>Test results</h2>

<pre><code>Method                   : Samoa   DST
relativedelta            :     0     0
timedelta                :     0     0
timedelta+conversion     :     1     0
timedelta+conversion+dst :     1     1
</code></pre>


blocks|key|986979|text|你也可以导入时间增量，这样代码就更整洁了。|type|unstyled|depth|inlineStyleRanges|entityRanges|data|986980|from+datetime+import+datetime,+timedelta
date+=+datetime.now()+%2B+timedelta(seconds=[delta_value])|code-block|syntax|javascript|986981|然后将日期转换为字符串|986982|date+=+date.strftime('%25Y-%25m-%25d+%25H:%25M:%25S')|986983|Python+one+liner是|986984|date+=+(datetime.now()+%2B+timedelta(seconds=[delta_value])).strftime('%25Y-%25m-%25d+%25H:%25M:%25S')|986985|entityMap^0|0|0|0|0|0|0^^$0|@$1|2|3|4|5|6|7|Q|8|@]|9|@]|A|$]]|$1|B|3|C|5|D|7|R|8|@]|9|@]|A|$E|F]]|$1|G|3|H|5|6|7|S|8|@]|9|@]|A|$]]|$1|I|3|J|5|D|7|T|8|@]|9|@]|A|$E|F]]|$1|K|3|L|5|6|7|U|8|@]|9|@]|A|$]]|$1|M|3|N|5|D|7|V|8|@]|9|@]|A|$E|F]]|$1|O|3|-4|5|6|7|W|8|@]|9|@]|A|$]]]|P|$]]

<p>You can also import timedelta so the code is cleaner.  </p>

<pre><code>from datetime import datetime, timedelta
date = datetime.now() + timedelta(seconds=[delta_value])
</code></pre>

<p>Then convert to date to string</p>

<pre><code>date = date.strftime('%Y-%m-%d %H:%M:%S')
</code></pre>

<p>Python one liner is</p>

<pre><code>date = (datetime.now() + timedelta(seconds=[delta_value])).strftime('%Y-%m-%d %H:%M:%S')
</code></pre>


blocks|key|987028|text|对我来说，这是一个简单的解决方案：|type|unstyled|depth|inlineStyleRanges|entityRanges|data|987029|from+datetime+import+timedelta,+datetime

today+=+datetime.today().strftime("%25Y-%25m-%25d")
tomorrow+=+datetime.today()+%2B+timedelta(1)|code-block|syntax|javascript|987030|entityMap^0|0|0^^$0|@$1|2|3|4|5|6|7|I|8|@]|9|@]|A|$]]|$1|B|3|C|5|D|7|J|8|@]|9|@]|A|$E|F]]|$1|G|3|-4|5|6|7|K|8|@]|9|@]|A|$]]]|H|$]]

<p>This was a straightforward solution for me:</p>

<pre class="lang-py prettyprint-override"><code>from datetime import timedelta, datetime

today = datetime.today().strftime("%Y-%m-%d")
tomorrow = datetime.today() + timedelta(1)

</code></pre>


<p>How to increment the day of a datetime?</p>

<pre><code>for i in range(1, 35)
    date = datetime.datetime(2003, 8, i)
    print(date)
</code></pre>

<p>But I need pass through months and years correctly? Any ideas?</p>


How to increment a datetime by one day?

Python

如何增加datetime的日期？for i in range(1, 35)    date = datetime.datetime(2003, 8, i)    print(date)但是我需要正确地通过月份和年份吗？有什么想法吗？

问如何将datetime递增一天？
EN

社区

活动

资源

关于

腾讯云开发者

热门产品

热门推荐

更多推荐

问如何将datetime递增一天？EN

社区

活动

资源

关于

腾讯云开发者

热门产品

热门推荐

更多推荐

问如何将datetime递增一天？
EN