Creating and Manipulating Date/Time Objects in Python

1. Creating Date and Time Objects

Creating Date Objects

python

from datetime import date, time, datetime

# Create date objects
date1 = date(2023, 12, 25)  # Christmas 2023
date2 = date(2024, 1, 1)    # New Year 2024
date3 = date(2023, 6, 15)   # Random date

print("Date Objects:")
print(f"Christmas: {date1}")
print(f"New Year: {date2}")
print(f"Random date: {date3}")

Creating Time Objects

python

# Create time objects
time1 = time(14, 30, 45)        # 2:30:45 PM
time2 = time(9, 0, 0)           # 9:00:00 AM
time3 = time(23, 45, 30, 500000) # 11:45:30.500000 PM

print("\nTime Objects:")
print(f"Time 1: {time1}")
print(f"Time 2: {time2}")
print(f"Time 3: {time3}")

Creating DateTime Objects

python

# Create datetime objects
dt1 = datetime(2023, 12, 25, 14, 30, 45)  # Christmas afternoon
dt2 = datetime(2024, 1, 1, 0, 0, 0)       # New Year midnight
dt3 = datetime(2023, 6, 15, 9, 15, 30)    # Random datetime

print("\nDateTime Objects:")
print(f"Christmas: {dt1}")
print(f"New Year: {dt2}")
print(f"Random: {dt3}")

2. Using combine() Method

Combine Date and Time

python

from datetime import date, time, datetime

# Create separate date and time
my_date = date(2023, 12, 25)
my_time = time(18, 30, 0)  # 6:30 PM

# Combine them into datetime
combined_dt = datetime.combine(my_date, my_time)
print(f"Combined DateTime: {combined_dt}")
# Output: 2023-12-25 18:30:00

# Multiple combinations
dates = [date(2023, 12, 25), date(2024, 1, 1), date(2024, 2, 14)]
times = [time(9, 0, 0), time(14, 30, 0), time(19, 0, 0)]

for d, t in zip(dates, times):
    combined = datetime.combine(d, t)
    print(f"{d} at {t} -> {combined}")

3. Comparing Objects

Date Comparisons

python

from datetime import date

# Create dates
today = date(2023, 12, 25)
tomorrow = date(2023, 12, 26)
yesterday = date(2023, 12, 24)

print("Date Comparisons:")
print(f"today > yesterday: {today > yesterday}")  # True
print(f"today < tomorrow: {today < tomorrow}")    # True
print(f"today == yesterday: {today == yesterday}") # False

# Check if date is in range
start_date = date(2023, 12, 1)
end_date = date(2023, 12, 31)
print(f"Is today in December 2023? {start_date <= today <= end_date}")  # True

DateTime Comparisons

python

from datetime import datetime

# Create datetimes
meeting1 = datetime(2023, 12, 25, 10, 0, 0)
meeting2 = datetime(2023, 12, 25, 14, 0, 0)
meeting3 = datetime(2023, 12, 26, 10, 0, 0)

print("\nDateTime Comparisons:")
print(f"Meeting1 before Meeting2: {meeting1 < meeting2}")  # True
print(f"Meeting2 after Meeting3: {meeting2 > meeting3}")   # False
print(f"Same day different times: {meeting1.date() == meeting2.date()}")  # True

4. Adding and Subtracting Objects

Using timedelta for Arithmetic

python

from datetime import datetime, timedelta

current_dt = datetime(2023, 12, 25, 10, 0, 0)
print(f"Current: {current_dt}")

# Adding time
one_day_later = current_dt + timedelta(days=1)
three_hours_later = current_dt + timedelta(hours=3)
one_week_later = current_dt + timedelta(weeks=1)

print(f"One day later: {one_day_later}")
print(f"Three hours later: {three_hours_later}")
print(f"One week later: {one_week_later}")

# Subtracting time
one_day_ago = current_dt - timedelta(days=1)
two_hours_ago = current_dt - timedelta(hours=2)

print(f"One day ago: {one_day_ago}")
print(f"Two hours ago: {two_hours_ago}")

Complex Date Arithmetic

python

from datetime import datetime, timedelta

# Project timeline example
project_start = datetime(2023, 12, 25, 9, 0, 0)

# Add various time periods
design_end = project_start + timedelta(days=7)  # 1 week for design
development_end = design_end + timedelta(days=14)  # 2 weeks for development
testing_end = development_end + timedelta(days=7)  # 1 week for testing

print("Project Timeline:")
print(f"Start: {project_start}")
print(f"Design complete: {design_end}")
print(f"Development complete: {development_end}")
print(f"Testing complete: {testing_end}")

# Calculate total project duration
total_duration = testing_end - project_start
print(f"Total project duration: {total_duration.days} days")

5. Complete Example Programs

Program 1: Event Scheduler

python

from datetime import datetime, timedelta, date, time

class EventScheduler:
    def __init__(self):
        self.events = []
    
    def add_event(self, name, event_date, event_time, duration_hours=1):
        event_dt = datetime.combine(event_date, event_time)
        end_time = event_dt + timedelta(hours=duration_hours)
        
        self.events.append({
            'name': name,
            'start': event_dt,
            'end': end_time
        })
        print(f"Event '{name}' scheduled from {event_dt} to {end_time}")
    
    def list_events(self):
        print("\nScheduled Events:")
        for event in sorted(self.events, key=lambda x: x['start']):
            duration = event['end'] - event['start']
            print(f"- {event['name']}: {event['start']} to {event['end']} ({duration})")

# Usage
scheduler = EventScheduler()

# Schedule events
scheduler.add_event("Team Meeting", date(2023, 12, 26), time(10, 0, 0), 2)
scheduler.add_event("Lunch", date(2023, 12, 26), time(12, 30, 0), 1)
scheduler.add_event("Client Call", date(2023, 12, 27), time(14, 0, 0), 1.5)

scheduler.list_events()

Program 2: Date Calculator

python

from datetime import date, timedelta

class DateCalculator:
    @staticmethod
    def calculate_age(birth_date):
        today = date.today()
        age = today.year - birth_date.year
        
        # Check if birthday hasn't occurred this year yet
        if today.month < birth_date.month or (today.month == birth_date.month and today.day < birth_date.day):
            age -= 1
        
        return age
    
    @staticmethod
    def days_until(target_date):
        today = date.today()
        return (target_date - today).days
    
    @staticmethod
    def add_business_days(start_date, business_days):
        current_date = start_date
        added_days = 0
        
        while added_days < business_days:
            current_date += timedelta(days=1)
            # Skip weekends (0=Monday, 6=Sunday)
            if current_date.weekday() < 5:
                added_days += 1
        
        return current_date

# Usage
calculator = DateCalculator()

# Calculate age
birthday = date(1990, 6, 15)
age = calculator.calculate_age(birthday)
print(f"Age: {age} years")

# Days until New Year
new_year = date(2024, 1, 1)
days_left = calculator.days_until(new_year)
print(f"Days until New Year: {days_left}")

# Add business days
start = date(2023, 12, 25)  # Monday
deadline = calculator.add_business_days(start, 5)  # Add 5 business days
print(f"Start: {start}, Deadline: {deadline}")

Program 3: Time Difference Calculator

python

from datetime import datetime

class TimeDifferenceCalculator:
    @staticmethod
    def time_between(dt1, dt2):
        difference = abs(dt2 - dt1)
        
        days = difference.days
        seconds = difference.seconds
        hours = seconds // 3600
        minutes = (seconds % 3600) // 60
        seconds = seconds % 60
        
        return {
            'total_seconds': difference.total_seconds(),
            'days': days,
            'hours': hours,
            'minutes': minutes,
            'seconds': seconds
        }
    
    @staticmethod
    def format_difference(dt1, dt2):
        diff = TimeDifferenceCalculator.time_between(dt1, dt2)
        
        if dt1 < dt2:
            direction = "after"
        else:
            direction = "before"
        
        parts = []
        if diff['days'] > 0:
            parts.append(f"{diff['days']} days")
        if diff['hours'] > 0:
            parts.append(f"{diff['hours']} hours")
        if diff['minutes'] > 0:
            parts.append(f"{diff['minutes']} minutes")
        if diff['seconds'] > 0:
            parts.append(f"{diff['seconds']} seconds")
        
        time_str = ", ".join(parts)
        return f"{dt2} is {time_str} {direction} {dt1}"

# Usage
calculator = TimeDifferenceCalculator()

# Calculate differences
start_time = datetime(2023, 12, 25, 10, 0, 0)
end_time = datetime(2023, 12, 26, 14, 30, 45)

difference = calculator.time_between(start_time, end_time)
print("Time Difference:")
for unit, value in difference.items():
    print(f"{unit}: {value}")

formatted = calculator.format_difference(start_time, end_time)
print(f"\nFormatted: {formatted}")

Key Points to Remember:

1. Creating Objects:
   • date(year, month, day)
   • time(hour, minute, second)
   • datetime(year, month, day, hour, minute, second)
2. Combining: Use datetime.combine(date, time)
3. Comparing: Use standard operators (<, >, ==, etc.)
4. Arithmetic: Use timedelta for adding/subtracting time
5. Always import: from datetime import date, time, datetime, timedelta

These examples show how powerful and flexible Python’s datetime module is for handling all kinds of date and time operations!