Date and Time (datetime module)

import datetime
 
# Hoặc import specific classes
from datetime import date, time, datetime, timedelta

from datetime import date
 
# Tạo date cụ thể
d = date(2024, 12, 25)
print(d)  # 2024-12-25
 
# Ngày hôm nay
today = date.today()
print(today)  # 2024-12-10 (ví dụ)

from datetime import date
 
today = date.today()
print(f"Năm: {today.year}")       # 2024
print(f"Tháng: {today.month}")    # 12
print(f"Ngày: {today.day}")       # 10

from datetime import date
 
today = date.today()
 
# Thứ trong tuần (0=Monday, 6=Sunday)
print(today.weekday())  # 1 (Tuesday)
 
# Thứ trong tuần (1=Monday, 7=Sunday)
print(today.isoweekday())  # 2 (Tuesday)
 
# Format ISO
print(today.isoformat())  # 2024-12-10
 
# Tên thứ
days = ["Monday", "Tuesday", "Wednesday", "Thursday", "Friday", "Saturday", "Sunday"]
print(days[today.weekday()])  # Tuesday

from datetime import date
 
# Tính tuổi
def calculate_age(birth_date):
    today = date.today()
    age = today.year - birth_date.year
 
    # Điều chỉnh nếu chưa đến sinh nhật
    if (today.month, today.day) < (birth_date.month, birth_date.day):
        age -= 1
 
    return age
 
birthday = date(2000, 5, 15)
age = calculate_age(birthday)
print(f"Tuổi: {age}")

from datetime import time
 
# Tạo time cụ thể
t = time(14, 30, 45)  # 14:30:45
print(t)
 
# Với microseconds
t = time(14, 30, 45, 123456)
print(t)  # 14:30:45.123456

from datetime import time
 
t = time(14, 30, 45, 123456)
print(f"Giờ: {t.hour}")              # 14
print(f"Phút: {t.minute}")           # 30
print(f"Giây: {t.second}")           # 45
print(f"Microsecond: {t.microsecond}")  # 123456

from datetime import datetime
 
# Ngày và giờ hiện tại
now = datetime.now()
print(now)  # 2024-12-10 14:30:45.123456
 
# UTC time
utc_now = datetime.utcnow()
print(utc_now)
 
# Tạo datetime cụ thể
dt = datetime(2024, 12, 25, 14, 30, 45)
print(dt)  # 2024-12-25 14:30:45

from datetime import datetime
 
now = datetime.now()
print(f"Năm: {now.year}")
print(f"Tháng: {now.month}")
print(f"Ngày: {now.day}")
print(f"Giờ: {now.hour}")
print(f"Phút: {now.minute}")
print(f"Giây: {now.second}")
print(f"Microsecond: {now.microsecond}")

from datetime import datetime
 
now = datetime.now()
 
# Lấy date
date_part = now.date()
print(date_part)  # 2024-12-10
 
# Lấy time
time_part = now.time()
print(time_part)  # 14:30:45.123456

from datetime import datetime, date, time
 
d = date(2024, 12, 25)
t = time(14, 30, 45)
 
# Kết hợp date và time
dt = datetime.combine(d, t)
print(dt)  # 2024-12-25 14:30:45

from datetime import datetime
 
now = datetime.now()
 
# Các format phổ biến
print(now.strftime("%Y-%m-%d"))           # 2024-12-10
print(now.strftime("%d/%m/%Y"))           # 10/12/2024
print(now.strftime("%H:%M:%S"))           # 14:30:45
print(now.strftime("%Y-%m-%d %H:%M:%S"))  # 2024-12-10 14:30:45
print(now.strftime("%A, %B %d, %Y"))      # Tuesday, December 10, 2024

from datetime import datetime
 
# Parse string
date_string = "2024-12-25 14:30:45"
dt = datetime.strptime(date_string, "%Y-%m-%d %H:%M:%S")
print(dt)  # 2024-12-25 14:30:45
 
# Các format khác
dt = datetime.strptime("25/12/2024", "%d/%m/%Y")
print(dt)  # 2024-12-25 00:00:00
 
dt = datetime.strptime("Dec 25, 2024", "%b %d, %Y")
print(dt)  # 2024-12-25 00:00:00

from datetime import datetime
 
# Parse nhiều format
def parse_date(date_string):
    formats = [
        "%Y-%m-%d",
        "%d/%m/%Y",
        "%m/%d/%Y",
        "%Y/%m/%d",
        "%d-%m-%Y"
    ]
 
    for fmt in formats:
        try:
            return datetime.strptime(date_string, fmt)
        except ValueError:
            continue
 
    raise ValueError(f"Cannot parse date: {date_string}")
 
# Test
dates = ["2024-12-10", "10/12/2024", "12/10/2024"]
for date_str in dates:
    try:
        dt = parse_date(date_str)
        print(f"{date_str} -> {dt}")
    except ValueError as e:
        print(e)

from datetime import timedelta
 
# Tạo khoảng thời gian
delta = timedelta(days=7)
print(delta)  # 7 days, 0:00:00
 
delta = timedelta(hours=2, minutes=30)
print(delta)  # 2:30:00
 
delta = timedelta(weeks=2, days=3, hours=4, minutes=30, seconds=15)
print(delta)  # 17 days, 4:30:15

from datetime import datetime, timedelta
 
now = datetime.now()
 
# Cộng thời gian
tomorrow = now + timedelta(days=1)
print(f"Tomorrow: {tomorrow}")
 
next_week = now + timedelta(weeks=1)
print(f"Next week: {next_week}")
 
# Trừ thời gian
yesterday = now - timedelta(days=1)
print(f"Yesterday: {yesterday}")
 
# Cộng nhiều đơn vị
future = now + timedelta(days=7, hours=12, minutes=30)
print(f"Future: {future}")

from datetime import datetime, timedelta
 
# Tính số ngày giữa 2 ngày
start = datetime(2024, 1, 1)
end = datetime(2024, 12, 31)
 
diff = end - start
print(f"Số ngày: {diff.days}")  # 365
print(f"Tổng giây: {diff.total_seconds()}")
 
# Tính tuổi chính xác
birth_date = datetime(2000, 5, 15)
now = datetime.now()
age_delta = now - birth_date
age_years = age_delta.days / 365.25
print(f"Tuổi: {age_years:.1f} năm")

from datetime import datetime, timedelta
 
# Tính deadline
def add_business_days(start_date, days):
    """Thêm số ngày làm việc (bỏ qua thứ 7, CN)"""
    current = start_date
    added = 0
 
    while added < days:
        current += timedelta(days=1)
        # Nếu không phải thứ 7 (5) hoặc CN (6)
        if current.weekday() < 5:
            added += 1
 
    return current
 
today = datetime.now()
deadline = add_business_days(today, 10)
print(f"Deadline (10 ngày làm việc): {deadline.strftime('%Y-%m-%d')}")

from datetime import datetime, timedelta
import time
 
def countdown(target_date):
    while True:
        now = datetime.now()
        remaining = target_date - now
 
        if remaining.total_seconds() <= 0:
            print("Time's up!")
            break
 
        days = remaining.days
        hours, remainder = divmod(remaining.seconds, 3600)
        minutes, seconds = divmod(remainder, 60)
 
        print(f"\r{days}d {hours}h {minutes}m {seconds}s", end="")
        time.sleep(1)
 
# Countdown đến năm mới
new_year = datetime(2025, 1, 1, 0, 0, 0)
# countdown(new_year)  # Uncomment để chạy

from datetime import datetime, date
 
def calculate_detailed_age(birth_date):
    today = date.today()
 
    years = today.year - birth_date.year
    months = today.month - birth_date.month
    days = today.day - birth_date.day
 
    # Điều chỉnh nếu ngày âm
    if days < 0:
        months -= 1
        # Số ngày trong tháng trước
        prev_month = today.month - 1 if today.month > 1 else 12
        prev_year = today.year if today.month > 1 else today.year - 1
        days_in_prev_month = (date(prev_year, prev_month + 1, 1) - timedelta(days=1)).day
        days += days_in_prev_month
 
    # Điều chỉnh nếu tháng âm
    if months < 0:
        years -= 1
        months += 12
 
    return years, months, days
 
birthday = date(2000, 5, 15)
years, months, days = calculate_detailed_age(birthday)
print(f"Tuổi: {years} năm, {months} tháng, {days} ngày")

from datetime import datetime, timedelta
 
class TimeTracker:
    def __init__(self):
        self.start_time = None
        self.sessions = []
 
    def start(self):
        self.start_time = datetime.now()
        print(f"Started at {self.start_time.strftime('%H:%M:%S')}")
 
    def stop(self):
        if self.start_time:
            end_time = datetime.now()
            duration = end_time - self.start_time
            self.sessions.append(duration)
            print(f"Stopped at {end_time.strftime('%H:%M:%S')}")
            print(f"Duration: {duration}")
            self.start_time = None
 
    def total_time(self):
        total = sum(self.sessions, timedelta())
        hours, remainder = divmod(total.seconds, 3600)
        minutes, seconds = divmod(remainder, 60)
        return f"{hours}h {minutes}m {seconds}s"
 
# Sử dụng
tracker = TimeTracker()
tracker.start()
# ... làm việc ...
import time
time.sleep(2)
tracker.stop()
print(f"Total: {tracker.total_time()}")

from datetime import datetime, timedelta
 
class MeetingScheduler:
    def __init__(self):
        self.meetings = []
 
    def add_meeting(self, title, start_time, duration_minutes):
        end_time = start_time + timedelta(minutes=duration_minutes)
 
        # Check conflict
        for meeting in self.meetings:
            if self.has_conflict(start_time, end_time, meeting):
                return False, f"Conflict with {meeting['title']}"
 
        self.meetings.append({
            'title': title,
            'start': start_time,
            'end': end_time
        })
        return True, "Meeting added"
 
    def has_conflict(self, start, end, meeting):
        return (start < meeting['end'] and end > meeting['start'])
 
    def show_schedule(self):
        self.meetings.sort(key=lambda x: x['start'])
        for meeting in self.meetings:
            print(f"{meeting['start'].strftime('%H:%M')} - {meeting['end'].strftime('%H:%M')}: {meeting['title']}")
 
# Sử dụng
scheduler = MeetingScheduler()
today = datetime.now().replace(hour=9, minute=0, second=0, microsecond=0)
 
scheduler.add_meeting("Team Meeting", today, 60)
scheduler.add_meeting("Lunch", today + timedelta(hours=3), 60)
scheduler.show_schedule()

from datetime import datetime, timedelta
 
def date_range(start_date, end_date, step=1):
    """Generator cho range của dates"""
    current = start_date
    while current <= end_date:
        yield current
        current += timedelta(days=step)
 
# Sử dụng
start = datetime(2024, 12, 1)
end = datetime(2024, 12, 31)
 
print("Tất cả ngày trong tháng 12:")
for date in date_range(start, end):
    print(date.strftime("%Y-%m-%d %A"))
 
print("\nMỗi 7 ngày:")
for date in date_range(start, end, step=7):
    print(date.strftime("%Y-%m-%d"))

from datetime import datetime, timedelta
 
def get_upcoming_birthdays(birthdays, days_ahead=30):
    """Lấy sinh nhật sắp tới trong N ngày"""
    today = datetime.now().date()
    upcoming = []
 
    for name, birthday in birthdays.items():
        # Birthday năm nay
        this_year_birthday = birthday.replace(year=today.year)
 
        # Nếu đã qua, lấy năm sau
        if this_year_birthday < today:
            this_year_birthday = birthday.replace(year=today.year + 1)
 
        # Tính số ngày còn lại
        days_until = (this_year_birthday - today).days
 
        if 0 <= days_until <= days_ahead:
            upcoming.append((name, this_year_birthday, days_until))
 
    return sorted(upcoming, key=lambda x: x[2])
 
# Test
birthdays = {
    "Alice": datetime(1990, 12, 15).date(),
    "Bob": datetime(1985, 12, 20).date(),
    "Charlie": datetime(1995, 1, 5).date()
}
 
upcoming = get_upcoming_birthdays(birthdays, 60)
for name, date, days in upcoming:
    print(f"{name}: {date.strftime('%B %d')} (trong {days} ngày)")

from datetime import datetime, timedelta
 
def calculate_working_hours(check_in, check_out, break_minutes=60):
    """Tính giờ làm việc"""
    if isinstance(check_in, str):
        check_in = datetime.strptime(check_in, "%H:%M")
    if isinstance(check_out, str):
        check_out = datetime.strptime(check_out, "%H:%M")
 
    total_time = check_out - check_in
    break_time = timedelta(minutes=break_minutes)
    working_time = total_time - break_time
 
    hours = working_time.seconds / 3600
    return hours
 
# Test
hours = calculate_working_hours("09:00", "18:00", 60)
print(f"Giờ làm việc: {hours} giờ")  # 8.0 giờ
 
# Tính lương
hourly_rate = 50000
salary = hours * hourly_rate
print(f"Lương: {salary:,.0f} VND")

from datetime import datetime, timedelta
 
def generate_shifts(start_date, days, shift_hours=8):
    """Tạo lịch ca làm việc"""
    shifts = []
    current = start_date
 
    for day in range(days):
        # Ca sáng: 6:00 - 14:00
        morning = current.replace(hour=6, minute=0)
        shifts.append(("Morning", morning, morning + timedelta(hours=shift_hours)))
 
        # Ca chiều: 14:00 - 22:00
        afternoon = current.replace(hour=14, minute=0)
        shifts.append(("Afternoon", afternoon, afternoon + timedelta(hours=shift_hours)))
 
        # Ca đêm: 22:00 - 6:00
        night = current.replace(hour=22, minute=0)
        shifts.append(("Night", night, night + timedelta(hours=shift_hours)))
 
        current += timedelta(days=1)
 
    return shifts
 
# Sử dụng
start = datetime(2024, 12, 1)
shifts = generate_shifts(start, 7)
 
for shift_name, start, end in shifts[:5]:  # In 5 ca đầu
    print(f"{shift_name}: {start.strftime('%Y-%m-%d %H:%M')} - {end.strftime('%Y-%m-%d %H:%M')}")

from datetime import datetime, timezone, timedelta
 
# Tạo datetime với timezone
utc = timezone.utc
vietnam_tz = timezone(timedelta(hours=7))  # UTC+7
 
# UTC time
utc_time = datetime.now(utc)
print(f"UTC: {utc_time}")
 
# Vietnam time
vietnam_time = utc_time.astimezone(vietnam_tz)
print(f"Vietnam: {vietnam_time}")
 
# Convert
def utc_to_vietnam(utc_datetime):
    vietnam_tz = timezone(timedelta(hours=7))
    return utc_datetime.astimezone(vietnam_tz)
 
utc_now = datetime.now(timezone.utc)
vn_now = utc_to_vietnam(utc_now)
print(f"VN time: {vn_now.strftime('%Y-%m-%d %H:%M:%S')}")

from datetime import datetime, timedelta
 
class Reminder:
    def __init__(self, message, remind_at):
        self.message = message
        self.remind_at = remind_at
        self.notified = False
 
    def check(self):
        if not self.notified and datetime.now() >= self.remind_at:
            print(f"REMINDER: {self.message}")
            self.notified = True
            return True
        return False
 
# Tạo reminders
reminders = [
    Reminder("Meeting in 5 minutes", datetime.now() + timedelta(minutes=5)),
    Reminder("Lunch time", datetime.now().replace(hour=12, minute=0)),
    Reminder("End of day", datetime.now().replace(hour=17, minute=30))
]
 
# Check reminders (trong vòng lặp thực tế)
import time
for reminder in reminders:
    if reminder.check():
        print(f"Time: {datetime.now().strftime('%H:%M')}")

from datetime import datetime, timezone
 
# TỐT - Có timezone
dt = datetime.now(timezone.utc)
 
# TRÁNH - Không có timezone
dt = datetime.now()

from datetime import datetime
 
dt = datetime.now()
 
# TỐT - ISO format (dễ parse, standard)
iso_string = dt.isoformat()
print(iso_string)  # 2024-12-10T14:30:45.123456
 
# Parse lại
dt2 = datetime.fromisoformat(iso_string)

from datetime import datetime, timezone
 
dt1 = datetime.now(timezone.utc)
dt2 = datetime.now(timezone.utc)
 
# TỐT - Cùng timezone
if dt1 < dt2:
    print("dt1 earlier")

from datetime import datetime, timedelta
 
# TỐT
tomorrow = datetime.now() + timedelta(days=1)
 
# TRÁNH - Không chính xác
# tomorrow = datetime.now() + 86400  # seconds