Дата, время и часовые пояса

from datetime import date, time, datetime, timedelta

d = date(2026, 10, 25)
print(d, d.year, d.month, d.day, d.weekday(), d.isoweekday())   # weekday: пн=0 … вс=6
print(d.isocalendar())                                         # год, номер недели, день недели
dt = datetime(2026, 10, 25, 14, 30, 15)
print(dt, dt.date(), dt.time(), dt.hour)
print(datetime.combine(d, time(9, 0)))
print(date.today() > date(2000, 1, 1))

from datetime import date, datetime, timedelta

deadline = date(2026, 12, 31)
start = date(2026, 10, 25)
left = deadline - start                       # date - date = timedelta
print(left, left.days)
print(start + timedelta(weeks=2))             # date + timedelta = date
print(datetime(2026, 3, 1, 0, 30) - timedelta(hours=1))

meeting = timedelta(hours=1, minutes=45)
print(meeting.total_seconds() / 60, "минут", meeting * 3)
print(sorted([date(2026, 5, 1), date(2025, 12, 31), date(2026, 1, 15)]))

import calendar
from datetime import date

def add_month(d: date) -> date:
    year, month = (d.year + 1, 1) if d.month == 12 else (d.year, d.month + 1)
    last_day = calendar.monthrange(year, month)[1]       # сколько дней в месяце
    return d.replace(year=year, month=month, day=min(d.day, last_day))

print(add_month(date(2026, 1, 31)), add_month(date(2026, 12, 15)), add_month(date(2028, 1, 31)))
print(calendar.isleap(2028), calendar.monthrange(2026, 2))

from datetime import datetime

dt = datetime(2026, 10, 5, 9, 7, 3)
print(dt.strftime("%d.%m.%Y %H:%M"))          # datetime → строка
print(dt.strftime("%Y-%m-%d"), dt.strftime("%A, %d %B"), dt.strftime("%j-й день года"))
print(f"{dt:%d.%m.%y}")                       # формат прямо в f-строке

parsed = datetime.strptime("05.10.2026 09:07", "%d.%m.%Y %H:%M")   # строка → datetime
print(parsed, parsed == dt.replace(second=0))

print(dt.isoformat(), datetime.fromisoformat("2026-10-05T09:07:03+03:00"))

from datetime import datetime, timezone, timedelta

naive = datetime(2026, 10, 25, 14, 0)
utc_now = datetime.now(timezone.utc)
msk = timezone(timedelta(hours=3), "MSK")
moscow = datetime(2026, 10, 25, 14, 0, tzinfo=msk)

print(naive.tzinfo, moscow.tzinfo, moscow.isoformat())
print(moscow.astimezone(timezone.utc))                  # тот же момент в UTC
print(utc_now.tzinfo is timezone.utc)
try:
    print(naive < moscow)
except TypeError as e:
    print("TypeError:", e)                              # наивные и aware не сравниваются

import time
from datetime import datetime, timezone

ts = time.time()                                          # секунды с 1970-01-01 UTC
print(int(ts))
print(datetime.fromtimestamp(1_700_000_000, tz=timezone.utc))
print(int(datetime(2026, 1, 1, tzinfo=timezone.utc).timestamp()))

start = time.perf_counter()                              # для измерения длительности
sum(range(300_000))
print(f"{time.perf_counter() - start:.4f} c")