In this tutorial I will show you the different ways of working with dates and times in python. Which includes working with milliseconds. You should note this isn’t all available options just some that I have encountered over the years.
Install Python Packages:
Open cmd/terminal and if required navigate to your sites working folder. (note: if you are working in a virtual env you should ensure you source it first).
pip install python-dateutil
There are many different packages that we can use to work with date and times. You need to decide what is right for you.
dateutil:
The following will convert the date string you give it fast and easily. This gives you back the datetime object. Notice how we don’t need to pass it a date time format. To me this is very convenient.
from dateutil import parser date_str = '2017-06-06' date_time_str = '2017-06-07 12:34' date_time_str_2 = '2017-06-07 12:34:46' date_time_str_3 = '2017-06-07 12:34:42.234' result = parser.parse(date_str) print(result) #2017-06-06 00:00:00 result = parser.parse(date_time_str) print(result) #2017-06-07 12:34:00 result = parser.parse(date_time_str_2) print(result) #2017-06-07 12:34:46 result = parser.parse(date_time_str_3) print(result) #2017-06-07 12:34:42.234000
datetime:
The following will convert the date string you give it fast and easily. This gives you back the datetime object. Notice how we need to pass the format of the datetime. If you don’t you will get an exception. This is a convenient way if you know the format before hand. But that might not always be the case.
import datetime date_str = '2017-06-06' date_time_str = '2017-06-07 12:34' date_time_str_2 = '2017-06-07 12:34:46' date_time_str_3 = '2017-06-07 12:34:42.234' result = datetime.datetime.strptime(date_str, "%Y-%m-%d") print(result) #2017-06-06 00:00:00 result = datetime.datetime.strptime(date_time_str, "%Y-%m-%d %H:%M") print(result) #2017-06-07 12:34:00 result = datetime.datetime.strptime(date_time_str_2, "%Y-%m-%d %H:%M:%S") print(result) #2017-06-07 12:34:46 result = datetime.datetime.strptime(date_time_str_3, "%Y-%m-%d %H:%M:%S.%f") print(result) #2017-06-07 12:34:42.234000
The above all works however the following example will not. Why do you think this is?
import datetime
date_time_str = '2017-06-07 12:34:46'
try:
datetime.datetime.strptime(date_time_str, "%Y-%m-%d %H:%M:%S")
except:
pass #just for this example don't do this lol
The reason is because datetime expects the correct format to be supplied. We gave it hour minute second but not milliseconds. You will get the following exception (ValueError: unconverted data remains: .234)
Timestamps:
Sometimes we want to convert the date to unix (epoch) time or vise versa.
From Date:
from dateutil import parser from datetime import timezone date_time_str = '2017-06-07 17:34:42.234' result = parser.parse(date_time_str) timestamp = result.replace(tzinfo=timezone.utc).timestamp() print(timestamp) #1496856882.234
This gives us the timestamp as a float as 1496856882.234.
From Timestamp:
from dateutil import parser import datetime timestamp = 1496856882.234 result = datetime.datetime.fromtimestamp(timestamp) print(result) #2017-06-07 13:34:42.234000 result = datetime.datetime.utcfromtimestamp(timestamp) print(result) #2017-06-07 17:34:42.234000
Get Date Parts:
If you want to get specific date parts such as the year, month, day, hour, etc.
import datetime from dateutil import parser result = parser.parse(date_time_str_3) print(result) #2017-06-07 12:34:42.234000 year = result.year #2017 month = result.month #6 day = result.day #7 hour = result.hour #12 minute = result.minute #34 second = result.second #42 millisecond = result.microsecond #234000
Add To Date:
If you want to add time to a date.
import datetime from dateutil import parser from datetime import timezone, timedelta date_time_str = '2017-06-07 17:34:42.234' result = parser.parse(date_time_str) print(result) #2017-06-07 17:34:42.234000 timestamp = result.replace(tzinfo=timezone.utc).timestamp() print(timestamp) #1496856882.234 #Add 10 seconds to datetime new_time = int((datetime.datetime.fromtimestamp(timestamp) + timedelta(milliseconds=10000)).timestamp() * 1000) print(new_time) #1496856892234
As you can see you can 10 seconds has been added the datetime.
datetime strftime
from datetime import datetime
now = datetime.now()
datetime_str = now.strftime("%Y-%m-%d %H:%M:%S")
print(datetime_str)
datetime fromisoformat
from datetime import datetime
print(datetime.fromisoformat("2024-04-09 13:48:20"))