Question

我需要做的是取当前日期，并根据今天的日期确定两周付款期的第一天。支付期从星期六开始。例如，今天（12/30）属于12/20的支付期。我需要处理的所有信息都显示为2014年12月20日。有任何建议吗？

由于

Answer 1

使用构思here来计算两个日期之间的差异，您可以执行以下操作：

function calculatePeriodStart(targetDate) {
    
    // get first day of year
    var day1 = new Date(targetDate.getFullYear(), 0, 1);
    
    // move forward to first Saturday
    day1.setDate(7 - day1.getDay());

    //Get 2 weeks in milliseconds
    var two_weeks = 1000 * 60 * 60 * 24 * 14;
    
    // Calculate the difference in milliseconds
    var difference_ms = targetDate.getTime() - day1.getTime();
    
    // Convert back to fortnights
    var numFortnightsD = difference_ms/two_weeks;
    var numFortnights = Math.ceil(numFortnightsD);
    
    // handle if on a Saturday, so a new cycle
    if(numFortnightsD == numFortnights)
    {
        numFortnights++;
    }
    
    // add the number of fortnights
    // but take one off to get the current period
    day1.setDate(day1.getDate() + (numFortnights-1)*14);
    
    return day1;
}

// examples

console.log('-----');

// today
var today = new Date();
console.log(today + ' => ' + calculatePeriodStart(today) + ' (today)');

// just before midnight of new period
var today = new Date(2014, 11, 19, 23, 59, 59);
console.log(today + ' => ' + calculatePeriodStart(today) + ' (just before midnight of new period)');

// exactly on midnight of new period
today = new Date(2014, 11, 20);
console.log(today + ' => ' + calculatePeriodStart(today) + ' (exactly on midnight of new period)');

// just after midnight of new period
today = new Date(2014, 11, 20, 0, 0, 1)
console.log(today + ' => ' + calculatePeriodStart(today) + ' (just after midnight of new period)');

// just after midnight of new period next year
today = new Date(2015, 11, 19, 0, 0, 1);
console.log(today + ' => ' + calculatePeriodStart(today) + ' (just after midnight of new period next year)');

// earlier than 1st period in year
today = new Date(2014, 0, 2);
console.log(today + ' => ' + calculatePeriodStart(today) + ' (earlier than 1st period in year)');

calculatePeriodStart()将返回Date个对象。要格式化显示日期，您可以使用this answer。

如何根据当前日期显示两周时间段的第一天？

1 个答案: