PHPでうるう年を判定する！簡単3ステップと実用例10選

$year = 2024; // 判定したい年を指定

if ($year % 4 == 0) {
    if ($year % 100 == 0) {
        if ($year % 400 == 0) {
            echo $year . '年はうるう年です。';
        } else {
            echo $year . '年はうるう年ではありません。';
        }
    } else {
        echo $year . '年はうるう年です。';
    }
} else {
    echo $year . '年はうるう年ではありません。';
}

function is_leap($year) {
    if ($year % 4 == 0) {
        if ($year % 100 == 0) {
            if ($year % 400 == 0) {
                return true;
            } else {
                return false;
            }
        } else {
            return true;
        }
    } else {
        return false;
    }
}

$year = 2024; // 判定したい年を指定
if (is_leap($year)) {
    echo $year . '年はうるう年です。';
} else {
    echo $year . '年はうるう年ではありません。';
}

function days_until($year, $month, $day) {
    $days = 0;
    for ($i = 1; $i < $year; $i++) {
        $days += is_leap($i) ? 366 : 365;
    }
    for ($i = 1; $i < $month; $i++) {
        $days += days_in_month($i, $year);
    }
    $days += $day;
    return $days;
}

function generate_year_schedule($year) {
    $schedule = [];
    for ($month = 1; $month <= 12; $month++) {
        $days_in_month = ($month == 2 && is_leap($year)) ? 29 : cal_days_in_month(CAL_GREGORIAN, $month, $year);
        for ($day = 1; $day <= $days_in_month; $day++) {
            $schedule[] = sprintf('%d-%02d-%02d', $year, $month, $day);
        }
    }
    return $schedule;
}

function birthday_message($year, $month, $day, $name) {
    if ($month == 2 && $day == 29 && !is_leap($year)) {
        $message = "おめでとうございます、{$name}さん。今年はうるう年ではないので、2月28日にお祝いしましょう。";
    } else {
        $message = "おめでとうございます、{$name}さん。{$month}月{$day}日はあなたの特別な日です。";
    }
    return $message;
}

function calculate_yearly_average($year, $temperature_data) {
    $total = 0;
    $days_in_year = is_leap($year) ? 366 : 365;

    for ($i = 0; $i < $days_in_year; $i++) {
        $total += $temperature_data[$i];
    }

    return $total / $days_in_year;
}

function leap_year_birthday_message($year, $month, $day, $name) {
    if ($month == 2 && $day == 29 && !is_leap($year)) {
        $message = "特別な日に生まれた{$name}さん、お誕生日おめでとうございます。今年はうるう年ではないので、2月28日にお祝いしましょう。";
    } else {
        $message = "{$name}さん、お誕生日おめでとうございます。";
    }
    return $message;
}

function calculate_age($birth_year, $birth_month, $birth_day, $current_year, $current_month, $current_day) {
    if ($birth_month == 2 && $birth_day == 29 && !is_leap($current_year)) {
        $current_day = 28;
    }
    if ($birth_month < $current_month || ($birth_month == $current_month && $birth_day <= $current_day)) {
        return $current_year - $birth_year;
    } else {
        return $current_year - $birth_year - 1;
    }
}

function get_holidays($year) {
    $holidays = array();
    // 新年の日
    $holidays[] = "{$year}-01-01";
    // 成人の日
    $holidays[] = "{$year}-01-" . (is_leap($year) ? '10' : '09');
    // 建国記念の日
    $holidays[] = "{$year}-02-11";
    // 春分の日
    $holidays[] = "{$year}-03-21";
    // ...
    return $holidays;
}

import datetime

def calculate_interest(start_date, end_date, annual_interest_rate):
    # 期間を計算（終了日 - 開始日）
    period = (end_date - start_date).days
    # 金利を計算（単利計算）
    interest = period / 365 * annual_interest_rate
    return interest

start_date = datetime.date(2023, 1, 1)
end_date = datetime.date(2023, 12, 31)
annual_interest_rate = 0.02  # 2%の年利

print(calculate_interest(start_date, end_date, annual_interest_rate))

class Schedule:
    def __init__(self):
        self.schedule = {}

    def add_schedule(self, date, event):
        if date not in self.schedule:
            self.schedule[date] = []
        self.schedule[date].append(event)

    def check_schedule(self, date):
        return self.schedule.get(date, [])

my_schedule = Schedule()
my_schedule.add_schedule('2023-05-01', '新年会')
my_schedule.add_schedule('2023-05-01', '月次ミーティング')

print(my_schedule.check_schedule('2023-05-01'))

import datetime

def days_since(date):
    # 現在の日付を取得
    now = datetime.date.today()
    # 経過日数を計算（現在の日付 - 指定日付）
    elapsed_days = (now - date).days
    return elapsed_days

date = datetime.date(2023, 1, 1)

print(days_since(date))

import datetime

def days_until(date):
    # 現在の日付を取得
    now = datetime.date.today()
    # 残り日数を計算（指定日付 - 現在の日付）
    remaining_days = (date - now).days
    return remaining_days

date = datetime.date(2023, 12, 31)

print(days_until(date))