Work with a time span in Javascript

Question

Using Date.js already, but can also use another library if necessary.

Not sure what is the best way to work with time deltas. Specifically, I want to display the tim

Answer 1

Here a .NET C# similar implementation of a timespan class that supports days, hours, minutes and seconds. This implementation also supports negative timespans.

const MILLIS_PER_SECOND = 1000;
const MILLIS_PER_MINUTE = MILLIS_PER_SECOND * 60;   //     60,000
const MILLIS_PER_HOUR = MILLIS_PER_MINUTE * 60;     //  3,600,000
const MILLIS_PER_DAY = MILLIS_PER_HOUR * 24;        // 86,400,000

export class TimeSpan {
    private _millis: number;

    private static interval(value: number, scale: number): TimeSpan {
        if (Number.isNaN(value)) {
            throw new Error("value can't be NaN");
        }

        const tmp = value * scale;
        const millis = TimeSpan.round(tmp + (value >= 0 ? 0.5 : -0.5));
        if ((millis > TimeSpan.maxValue.totalMilliseconds) || (millis < TimeSpan.minValue.totalMilliseconds)) {
            throw new TimeSpanOverflowError("TimeSpanTooLong");
        }

        return new TimeSpan(millis);
    }

    private static round(n: number): number {
        if (n < 0) {
            return Math.ceil(n);
        } else if (n > 0) {
            return Math.floor(n);
        }

        return 0;
    }

    private static timeToMilliseconds(hour: number, minute: number, second: number): number {
        const totalSeconds = (hour * 3600) + (minute * 60) + second;
        if (totalSeconds > TimeSpan.maxValue.totalSeconds || totalSeconds < TimeSpan.minValue.totalSeconds) {
            throw new TimeSpanOverflowError("TimeSpanTooLong");
        }

        return totalSeconds * MILLIS_PER_SECOND;
    }

    public static get zero(): TimeSpan {
        return new TimeSpan(0);
    }

    public static get maxValue(): TimeSpan {
        return new TimeSpan(Number.MAX_SAFE_INTEGER);
    }

    public static get minValue(): TimeSpan {
        return new TimeSpan(Number.MIN_SAFE_INTEGER);
    }

    public static fromDays(value: number): TimeSpan {
        return TimeSpan.interval(value, MILLIS_PER_DAY);
    }

    public static fromHours(value: number): TimeSpan {
        return TimeSpan.interval(value, MILLIS_PER_HOUR);
    }

    public static fromMilliseconds(value: number): TimeSpan {
        return TimeSpan.interval(value, 1);
    }

    public static fromMinutes(value: number): TimeSpan {
        return TimeSpan.interval(value, MILLIS_PER_MINUTE);
    }

    public static fromSeconds(value: number): TimeSpan {
        return TimeSpan.interval(value, MILLIS_PER_SECOND);
    }

    public static fromTime(hours: number, minutes: number, seconds: number): TimeSpan;
    public static fromTime(days: number, hours: number, minutes: number, seconds: number, milliseconds: number): TimeSpan;
    public static fromTime(daysOrHours: number, hoursOrMinutes: number, minutesOrSeconds: number, seconds?: number, milliseconds?: number): TimeSpan {
        if (milliseconds != undefined) {
            return this.fromTimeStartingFromDays(daysOrHours, hoursOrMinutes, minutesOrSeconds, seconds, milliseconds);
        } else {
            return this.fromTimeStartingFromHours(daysOrHours, hoursOrMinutes, minutesOrSeconds);
        }
    }

    private static fromTimeStartingFromHours(hours: number, minutes: number, seconds: number): TimeSpan {
        const millis = TimeSpan.timeToMilliseconds(hours, minutes, seconds);
        return new TimeSpan(millis);
    }

    private static fromTimeStartingFromDays(days: number, hours: number, minutes: number, seconds: number, milliseconds: number): TimeSpan {
        const totalMilliSeconds = (days * MILLIS_PER_DAY) +
            (hours * MILLIS_PER_HOUR) +
            (minutes * MILLIS_PER_MINUTE) +
            (seconds * MILLIS_PER_SECOND) +
            milliseconds;

        if (totalMilliSeconds > TimeSpan.maxValue.totalMilliseconds || totalMilliSeconds < TimeSpan.minValue.totalMilliseconds) {
            throw new TimeSpanOverflowError("TimeSpanTooLong");
        }
        return new TimeSpan(totalMilliSeconds);
    }

    constructor(millis: number) {
        this._millis = millis;
    }

    public get days(): number {
        return TimeSpan.round(this._millis / MILLIS_PER_DAY);
    }

    public get hours(): number {
        return TimeSpan.round((this._millis / MILLIS_PER_HOUR) % 24);
    }

    public get minutes(): number {
        return TimeSpan.round((this._millis / MILLIS_PER_MINUTE) % 60);
    }

    public get seconds(): number {
        return TimeSpan.round((this._millis / MILLIS_PER_SECOND) % 60);
    }

    public get milliseconds(): number {
        return TimeSpan.round(this._millis % 1000);
    }

    public get totalDays(): number {
        return this._millis / MILLIS_PER_DAY;
    }

    public get totalHours(): number {
        return this._millis / MILLIS_PER_HOUR;
    }

    public get totalMinutes(): number {
        return this._millis / MILLIS_PER_MINUTE;
    }

    public get totalSeconds(): number {
        return this._millis / MILLIS_PER_SECOND;
    }

    public get totalMilliseconds(): number {
        return this._millis;
    }

    public add(ts: TimeSpan): TimeSpan {
        const result = this._millis + ts.totalMilliseconds;
        return new TimeSpan(result);
    }

    public subtract(ts: TimeSpan): TimeSpan {
        const result = this._millis - ts.totalMilliseconds;
        return new TimeSpan(result);
    }
}

How to use

Create a new TimeSpan object

From zero

    const ts = TimeSpan.zero;

From milliseconds

    const milliseconds = 10000; // 1 second

    // by using the constructor
    const ts1 = new TimeSpan(milliseconds);

    // or as an alternative you can use the static factory method
    const ts2 = TimeSpan.fromMilliseconds(milliseconds);

From seconds

    const seconds = 86400; // 1 day
    const ts = TimeSpan.fromSeconds(seconds);

From minutes

    const minutes = 1440; // 1 day
    const ts = TimeSpan.fromMinutes(minutes);

From hours

    const hours = 24; // 1 day
    const ts = TimeSpan.fromHours(hours);

From days

    const days = 1; // 1 day
    const ts = TimeSpan.fromDays(days);

From time with given hours, minutes and seconds

    const hours = 1;
    const minutes = 1;
    const seconds = 1;
    const ts = TimeSpan.fromTime(hours, minutes, seconds);

From time2 with given days, hours, minutes, seconds and milliseconds

    const days = 1;
    const hours = 1;
    const minutes = 1;
    const seconds = 1;
    const milliseconds = 1;
    const ts = TimeSpan.fromTime(days, hours, minutes, seconds, milliseconds);

From maximal safe integer

    const ts = TimeSpan.maxValue;

From minimal safe integer

    const ts = TimeSpan.minValue;

From minimal safe integer

    const ts = TimeSpan.minValue;

Add

    const ts1 = TimeSpan.fromDays(1);
    const ts2 = TimeSpan.fromHours(1);
    const ts = ts1.add(ts2);

    console.log(ts.days);               // 1
    console.log(ts.hours);              // 1
    console.log(ts.minutes);            // 0
    console.log(ts.seconds);            // 0
    console.log(ts.milliseconds);           // 0

Subtract

    const ts1 = TimeSpan.fromDays(1);
    const ts2 = TimeSpan.fromHours(1);
    const ts = ts1.subtract(ts2);

    console.log(ts.days);               // 0
    console.log(ts.hours);              // 23
    console.log(ts.minutes);            // 0
    console.log(ts.seconds);            // 0
    console.log(ts.milliseconds);           // 0

Getting the intervals

    const days = 1;
    const hours = 1;
    const minutes = 1;
    const seconds = 1;
    const milliseconds = 1;
    const ts = TimeSpan.fromTime2(days, hours, minutes, seconds, milliseconds);

    console.log(ts.days);               // 1
    console.log(ts.hours);              // 1
    console.log(ts.minutes);            // 1
    console.log(ts.seconds);            // 1
    console.log(ts.milliseconds);           // 1

    console.log(ts.totalDays)           // 1.0423726967592593;
    console.log(ts.totalHours)          // 25.016944722222224;
    console.log(ts.totalMinutes)            // 1501.0166833333333;
    console.log(ts.totalSeconds)            // 90061.001;
    console.log(ts.totalMilliseconds);      // 90061001;

See also here: https://github.com/erdas/timespan