Minute based calculation to Date - Node.js Date

Node.js examples for Date:Date Calculation

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Description

Minute based calculation to Date

Demo Code

//-----------------------------------------------------------------------------
//  DateUtils.js is part of the BART dashboard widget.  (c) 2005 Bret Victor
//  This software is licensed under the terms of the open source MIT license.
//-----------------------------------------------------------------------------
////from  w  ww .  ja  v a  2 s. c  o m
//  Date-munging functions.
//

function dateNow () {
    return new Date()
}

function datePlusMinutes (date, minutes) {
    var ms = date.getTime() + minutes*60*1000
    return new Date(ms)
}

function getMinutesBetweenDates (date1, date2) {
    var ms = date2.getTime() - date1.getTime()
    return ms/1000/60
}

function minutesSinceMidnightToTimeString (minutes_since_midnight) {
    var hours = Math.floor(minutes_since_midnight / 60)
    var min   = minutes_since_midnight % 60
    var ampm = (hours < 12) ? "am" : "pm"
    if (hours == 0) { hours = 12 }
    else if (hours > 12) { hours = hours - 12 }
    if (min < 10) { min = "0" + min }
    return "" + hours + ":" + min + " " + ampm
}

// Accepts times in any of the forms:  "1:00 pm", "1:00 PM", "13:00", "13", "1300"
function timeStringToMinutesSinceMidnight (time_string, can_return_undefined) {
    var hours = 0;
    var min = 0;
    
    // Check for am/pm.
    var ampm = time_string.match(/am/i) ? "am"
             : time_string.match(/pm/i) ? "pm"
             : time_string.match(/a/i)  ? "am"
             : time_string.match(/p/i)  ? "pm" 
             : undefined

    // Try form "hh:mm".
    var matches = /(\d+)\:(\d+)/.exec(time_string)
    if (matches) {  hours = parseInt(matches[1]);  min = parseInt(matches[2])  }
    else {
        matches = /\d+/.exec(time_string)
        if (matches) {
            var number = parseInt(matches[0])
            // Try form "hhmm".
            if (number >= 100) {  hours = Math.floor(number / 100);  min = number % 100  }
            // Try form "hh".
            else {  hours = number;  min = 0  }
        }
        else {
            if (can_return_undefined) { return undefined }
        }
    }
    if (ampm == "pm" && hours < 12) { hours += 12 }
    else if (ampm == "am" && hours == 12) { hours = 0 }
    if (hours > 23) { hours = 23 }
    if (min > 59) { min = 59 }
    return hours * 60 + min
}

function dateToStringAsHHMM (date) {
    var hours = date.getHours()
    var min = date.getMinutes()
    if (hours == 0) { hours = 12 }
    else if (hours > 12) { hours = hours - 12 }
    if (min < 10) { min = "0" + min }
    return "" + hours + ":" + min
}

function getMinutesSinceMidnight (date) {
    var midnight = new Date(date.getFullYear(), date.getMonth(), date.getDate(), 0)
    return getMinutesBetweenDates(midnight,date)
}

// dateQuantizedDownToMinutes(ten_o_four, 15) == ten_o_clock
// dateQuantizedDownToMinutes(ten_fifty,  15) == ten_forty_five
function dateQuantizedDownToMinutes (date, minutes) {
    var offset = (getMinutesSinceMidnight(date) % minutes)
    return datePlusMinutes(date, -offset)
}

// dateAtEarlierHour(ten_am_on_saturday, 4) == four_am_on_saturday
// dateAtEarlierHour(two_am_on_saturday, 4) == four_am_on_friday
function dateAtEarlierHour (date, starting_hour) {
    var morning = new Date(date.getFullYear(), date.getMonth(), date.getDate(), starting_hour)
    if (date.getHours() < starting_hour) {
        // If it's after midnight, start counting from the previous day's morning
        morning = datePlusMinutes(morning, -60*24)
    }
    return morning
}

function isDateWeekend (date) {
    var day_of_week = date.getDay()
    return (day_of_week == 0 || day_of_week == 6)
}

Date.prototype.toMMDDYYYYString = function () {
    return isNaN (this) ? 'NaN' 
    : [ this.getMonth() > 8 ? this.getMonth() + 1 
                           : '0' + (this.getMonth() + 1), 
        this.getDate() > 9 ? this.getDate() 
                           : '0' + this.getDate(),
        this.getFullYear()].join('/')
}

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