Parse datetime in Python and JavaScript

Python

I recommend dateutil.

ref:
https://dateutil.readthedocs.org/en/latest/

import datetime
from dateutil import parser as dateutil_parser

>>> dateutil_parser.parse('2014-12-24T16:15:16')
datetime.datetime(2014, 12, 24, 16, 15, 16)

>>> datetime_obj = datetime.datetime.strptime('2014-12-24T16:15:16', '%Y-%m-%dT%H:%M:%S')
datetime.datetime(2014, 12, 24, 16, 15, 16)

>>> datetime_obj = datetime.datetime.strptime('201408282300', '%Y%m%d%H%M')
datetime.datetime(2014, 8, 28, 23, 0)

>>> datetime_obj.strftime('%Y-%m-%d %H:%M')

strftime >> datetime -> str
strptime >> str --> datetime

ref:
https://docs.python.org/2/library/datetime.html#strftime-and-strptime-behavior

Django Template

class DriverInfoForm(forms.ModelForm):
    service_time_start = forms.TimeField(
        widget=forms.TimeInput(format='%H:%M'),
        input_formats=['%H:%M', ]
    )

@register.filter
def str_to_time(time_str, output_format):
    """
    把字串轉成 datetime obj
    再依據 output_format 輸出

    {{ news.modified_at|str_to_time:"%Y/%m/%d %H:%M" }}
    """

    from dateutil import parser

    datetime_obj = parser.parse(time_str, fuzzy=True)

    return datetime_obj.strftime(output_format)

日期：{{ withdraw.presented_at|date:"%Y 年 %n 月" }}
聯絡時間：{{ driver.service_time_start|date:"H:i" }} - {{ driver.service_time_end|date:"H:i" }}

要注意的是，Django 似乎不能 parse AM / PM，所以儘量用 24 小時制。

ref:
https://docs.djangoproject.com/en/dev/ref/templates/builtins/#date

JavaScript

I recommend moment.js.

ref:
https://momentjs.com/

var today = new Date().toISOString().slice(0, 10);
// 2016-05-11

var t1 = new Date('2016-05-02T03:00:00.000+01:00');
// Mon May 02 2016 10:00:00 GMT+0800 (CST)

var t1_timestamp_ms = t1.getTime();
// 要注意的是 JavaScript 的 getTime() 的單位是 ms
// 1462154400000

var t1_timestamp = t1.getTime() / 1000;
// 1462154400

var t2 = new Date(1485596172 * 1000);
// Sat Jan 28 2017 17:36:12 GMT+0800 (CST)

var t3 = moment('201408292300', 'YYYYMMDDHHmm');

var t3 = moment('2018-02-02')
var timestamp = time.unix()
// 單位是 second
// 1518192000

ref:
https://stackoverflow.com/questions/3552461/how-to-format-a-javascript-date