Datetime handling the python way (or as close as possible)
npm install py-datetimeThis tiny lib emulates most of the main functions of Python's datetime lib to simplify datetime handling in JavaScript that is notoriously cumbersome in this regard.
It tries to stay as close to the python API as possible - ideal if you are working with both Python and JS projects.
Hope you'll find it useful!
Live console here: https://npm.runkit.com/py-datetime
``npm install py-datetime`
javascript
import {default as dt} from "py-datetime"; // const dt = require("py-datetime"); for node importslet now = dt.datetime.now()
let today = dt.datetime.combine(now, dt.time())
console.log("Now:", now.strftime("%Y-%m-%d %H:%M:%S"));
console.log("Today:", today.strftime("%Y-%m-%d"));
console.log("Minutes since midnight:", dt.timedelta(now - today).totalSeconds() / 60);
`A few gotchas
*
constructor can't really guess whether you are passing in a day or a result
from date math (as dt - dt in javascript will return an int), so i've arbitrarily put in a condition where if it's under
900 we treat it as days, but otherwise it's millis (1000 millis = 1 sec). For most cases this should work just fine, but
where disambiguation is required, you can be be explicit about it: dt.timedelta({days: ..}) and
dt.timedelta({millisesconds: ..}), respectively..str() to get string representation of the object. JavaScript's toString() will return Unix epoch.Note: all objects evaluate to milliseconds, meaning dt.datetime.now() + 0 will give you time in Unix epoch. you can also call directly.
dt.datetime* dt.datetime(year, month, day, hour, minute, second, millisecond) - gets you a brand new datetime
* dt.datetime(jsDate) - you can also pass in a JavaScript Date object
* dt.datetime(unixEpoch) - this will also work
* dt.datetime(datetime) - this will clone an existing datetime object)
* dt.datetime.strptime(dateString, format, utc) - parse given date string into a new datetime. Format uses posix parsing
see [d3-time-format
dt.datetime.now() - return current timedt.datetime.utcnow() - return current time in UTCdt.datetime.combine(date, time) - combines passed in dt.date or dt.datetime with the passed in dt.time to create a new datetimedatetime.replace(year, month, day, hour, minute, second, millisecond) returns a new datetime with items replaced as requesteddatetime.jsDate property returns JavaScript Date object representing the datetimedatetime.str() returns analog of python's str(datetime) which is %Y-%m-%d %H:%M:%S.%fdt.date* dt.date(year, month, day) - creates a, well, timeless object, all three params are mandatory
* date.jsDate property returns JavaScript Date object representing the datetime
* datetime.str() returns analog of python's str(date), which is %Y-%m-%d
dt.timedt.time(hour, minute, second, millisecond) - return a new time objectdt.time(time) - clone an existing dt.time objecttime.str() returns analog of python's str(time), which is %H:%M:%S.%fdt.timedeltadt.timedelta(days, seconds, milliseconds, minutes, hours, weeks) - return a new time object. the param order is not randomdt.timedelta(millis) - this will work if millis is > 900. will initiate the timedelta object from milliseconds. this is sodt.timedelta(dateA - dateB). See gotchas higher up for the 900 thing.timedelta.totalSeconds() - returns total seconds between the two times.timedelta.str() returns analog of python's str(time), which is %H:%M:%S.%fpy-datetime is timezone naive, but dates and times around daylight savings can get bit iffy. There are two functions
that help mitigate that
* dt.datetime.utc() - pass in JS datetime in UTC timezone or unix epoch. the datetime object will be marked as operating in UTC
* dt.datetime.strptime - if you pass in the date string in UTC, make sure to specify the third optional param to true.
from there on out this date object will be marked as operating in UTC.
Be mindful around datemath, e.g. z = dt.datetime(dt.datetime.utc(someDate) + dt.timedelta(1)) will lose the UTC information, so
you should do z = dt.datetime.utc(dt.datetime.utc(someDate) + dt.timedelta(1)).
The API is bit sucky at the moment, so if you have any good ideas - pull requests welcome!