programiz · parewa-ranjit · Feb 10, 2021 · Feb 8, 2021 · Feb 9, 2021
diff --git a/29-generators.md b/29-generators.md
@@ -1,6 +1,6 @@
 # Python Generators
 
-**Video link:** 
+**Video link:** [https://youtu.be/ebj4qZ8SyMU](https://youtu.be/ebj4qZ8SyMU)
 
 In this video, we learned how to create custom iterators in Python using generator functions.
 

diff --git a/30-datetime.md b/30-datetime.md
@@ -0,0 +1,239 @@
+# Python `datetime` module
+
+**Video link:** 
+
+In this video, we learned about the `datetime` module to manipulate date and time in Python.
+
+**Programs in the Video**
+
+- [Get Current Date](#get-current-date)
+- [The datetime.date Class](#the-datetimedate-class)
+- [The datetime.time Class](#the-datetimetime-class)
+- [The datetime.datetime Class](#the-datetimedatetime-class)
+- [Getting current date and time](#getting-current-date-and-time)
+- [The datetime.timedelta Class](#the-datetimetimedelta-class)
+- [Python `strftime()` method](#python-strftime-method)
+- [Python `strptime()` method](#python-strptime-method)
+
+---
+
+## Get Current Date
+We can find the current local date using the `today()` method of the `date` class of the `datetime` module:
+
+```python
+import datetime as dt
+
+current_date = dt.date.today()
+print(current_date)
+```
+
+**Output**
+```
+2021-02-10
+```
+
+Similar to the `date` class, the `datetime` module has many other useful classes to work with date and time:
+
+* `date` class - to work with date
+* `time` class - to work with time
+* `datetime` class - combination of `date` and `time` classes
+
+---
+
+## The datetime.date Class
+
+The `date` class of the `datetime` module is used to create `date` objects that can store year, month and day.
+
+```python
+import datetime as dt
+
+date1 = dt.date(2021, 1, 21)
+print(date1)
+
+print("Year:", date1.year)
+print("Month:", date1.month)
+print("Day:", date1.day)
+```
+
+**Output**
+
+```
+2021-01-21
+Year: 2021
+Month: 1
+Day: 21
+```
+
+---
+
+## The datetime.time Class
+
+The `time` class of the `datetime` module is used to create `time` objects that can store time of day like hours, minutes, seconds, and microseconds.
+
+The time class takes in all optional integer arguments. By default all of them are `0`.
+- The first argument is hour from `0` to `24`
+- The second one is minutes from `0` to `60`
+- The third is seconds from `0` to `60`
+- The fourth is microsecond from `0` to `999999`
+
+```python
+import datetime as dt
+
+time1 = dt.time(10, 47, 20, 234566)
+print(time1)
+
+print("Hour:", time1.hour)
+print("Minute:", time1.minute)
+print("Second:", time1.second)
+print("Microsecond:", time1.microsecond)
+
+```
+
+**Output**
+
+```
+10:47:20.234566
+Hour: 10
+Minute: 47
+Second: 20
+Microsecond: 234566
+```
+
+>**Note:** If you want more control and functionalities on time, use the `time` module.
+
+---
+
+## The datetime.datetime Class
+
+The `datetime` class of the `datetime` module is used to create objects that contain all the information from a `date` object as well as a `time` object.
+
+```python
+import datetime as dt
+datetime_obj = dt.datetime(2021, 11, 28, 23, 55, 59)
+
+print(datetime_obj)
+
+print(datetime_obj.date())
+print(datetime_obj.time())
+```
+
+**Output**
+```
+2021-11-28 23:55:59
+2021-11-28
+23:55:59
+```
+
+Like with `date` and `time` objects, we can also access individual attributes like `year`, `month` and `hour` as previously discussed.
+
+---
+
+## Getting current date and time
+
+To get the current local date and time at once, we can use the `now()` method of the `datetime` object.
+
+```python
+import datetime as dt
+
+current_time = dt.datetime.now()
+
+print(current_time)
+```
+
+**Output**
+```
+2021-01-21 05:56:45.817533
+```
+
+---
+
+## The datetime.timedelta Class
+
+A timedelta object represents the difference between two dates or times.
+
+Let's find out the time difference between now and the next new year.
+
+```python
+import datetime as dt
+
+current_time = dt.datetime.now()
+next_new_year = dt.datetime(2022, 1, 1)
+
+time_remaining = next_new_year - current_time
+
+print(time_remaining)
+print(type(time_remaining))
+```
+
+**Output**
+```
+324 days, 13:31:29.981402
+<class 'datetime.timedelta'>
+```
+
+This `timedelta` object can also be added or subtracted from `datetime` objects to get new `datetime` objects.
+
+---
+
+## Python `strftime()` method
+
+The `strftime()` method returns a string representing date and time for the datetime object.
+
+There are many formats to write the date and time depending on your location.
+
+If you are in the US, you probably use the `mm-dd-yyyy` format while if you're in the UK you will generally use the `dd-mm-yyyy` format. 
+
+The `strftime()` method allows us to display the date and time in a custom specific format.
+
+```python
+import datetime as dt
+
+current_datetime = dt.datetime.now()
+print(current_datetime)
+
+string_date = current_datetime.strftime("%A, %B %d, %Y")
+print(string_date)
+```
+
+**Output**
+```
+2021-01-21 06:20:19.627086
+Thursday, January 21, 2021
+```
+
+Here,
+- `%A` represents the weekday name i.e. `Thursday`
+- `%B` represents the month's full name
+- `%d` represents the day of the month
+- `%Y` represents the year
+
+There are many other format codes:
+
+| Directive | Meaning                                   | Example             |
+|-----------|-------------------------------------------|---------------------|
+| `%a`        | Abbreviated weekday name                  | Sun, Mon, ...       |
+| `%A`       | Full weekday name                         | Sunday, Monday, ... |
+| `%w`        | Weekday as a decimal number               | 0, 1, ..., 6        |
+| `%d`        | Day of the month as a zero-padded decimal | 01, 02, ..., 31     |
+| `%b`        | Abbreviated month name                    | Jan, Feb, ..., Dec  |
+| `%p`        | Locale’s AM or PM                         | AM, PM              |
+
+---
+
+## Python `strptime()` method
+
+The `strptime()` method converts strings to datetime objects.
+
+```python
+import datetime as dt
+
+date_string = "21 June, 2021"
+
+date_object = dt.datetime.strptime(date_string, "%d %B, %Y")
+print("date_object:", date_object)
+```
+
+**Output**
+```
+date_object: 2018-06-21 00:00:00
+```