# Python Datetime Module

The `datetime` module supplies classes for manipulating dates and times. While date and time arithmetic is supported, the focus of the implementation is on efficient attribute extraction for output formatting and manipulation.

## Importing the Module

```python
import datetime
```

## Common Classes

*   `datetime.date`: An idealized naive date, assuming the current Gregorian calendar extended in both directions. Attributes: year, month, and day.
*   `datetime.time`: An idealized time, independent of any particular day, assuming that every day has exactly 24*60*60 seconds. Attributes: hour, minute, second, microsecond, and tzinfo.
*   `datetime.datetime`: A combination of a date and a time. Attributes: year, month, day, hour, minute, second, microsecond, and tzinfo.
*   `datetime.timedelta`: A duration expressing the difference between two date, time, or datetime instances.

## Working with Dates

### Getting Today's Date

```python
from datetime import date

today = date.today()
print("Today's date:", today)
```

### Creating Date Objects

```python
d = date(2023, 4, 13)
print(d)
```

## Working with Datetime

### Getting Current Date and Time

```python
from datetime import datetime

now = datetime.now()
print("now =", now)
```

### Creating Datetime Objects

```python
dt = datetime(2023, 11, 28, 23, 55, 59, 342380)
print("dt =", dt)
```

## Date Arithmetic (`timedelta`)

`timedelta` objects represent a duration, the difference between two dates or times.

```python
from datetime import date, timedelta

today = date.today()
print("Today:", today)

# Add 7 days
next_week = today + timedelta(days=7)
print("Next week:", next_week)

# Subtract 1 day
yesterday = today - timedelta(days=1)
print("Yesterday:", yesterday)
```

## Formatting and Parsing

### `strftime()` - Date to String

The `strftime()` method creates a string representing the date under the control of an explicit format string.

```python
from datetime import datetime

now = datetime.now()

# Format: DD/MM/YYYY H:M:S
dt_string = now.strftime("%d/%m/%Y %H:%M:%S")
print("date and time =", dt_string)	
```

### `strptime()` - String to Date

The `strptime()` method creates a datetime object from a given string (representing date and time).

```python
from datetime import datetime

date_string = "21 June, 2023"
dt_object = datetime.strptime(date_string, "%d %B, %Y")

print("dt_object =", dt_object)
```

### Common Format Codes

*   `%Y`: Year with century as a decimal number.
*   `%m`: Month as a decimal number [01,12].
*   `%d`: Day of the month as a decimal number [01,31].
*   `%H`: Hour (24-hour clock) as a decimal number [00,23].
*   `%M`: Minute as a decimal number [00,59].
*   `%S`: Second as a decimal number [00,61].

[[programming/python/python]]