addMinutes()

Adds or subtracts minutes from a Date object.

Syntax

addMinutes(dateObj, minutes)

Parameters

Parameter	Type	Required	Description
dateObj	Date	Yes	The base Date object
minutes	number	Yes	Number of minutes to add (positive) or subtract (negative)

Returns

Date - A new Date object with the specified number of minutes added or subtracted

Basic Examples

Adding and Subtracting Minutes

import { addMinutes } from 'date-and-time';

const date = new Date(2024, 7, 15, 14, 30, 45); // August 15, 2024 14:30:45

// Add minutes
const future = addMinutes(date, 25);
console.log(future);  // August 15, 2024 14:55:45

// Subtract minutes
const past = addMinutes(date, -15);
console.log(past);  // August 15, 2024 14:15:45

Use Cases

Appointment Scheduling

function scheduleAppointments(startTime: Date, appointmentLength: number, count: number): Date[] {
  const appointments: Date[] = [];
  let currentTime = new Date(startTime);  

  for (let i = 0; i < count; i++) {
    appointments.push(new Date(currentTime));
    currentTime = addMinutes(currentTime, appointmentLength);
  }
  
  return appointments;
}

const firstAppointment = new Date(2024, 7, 15, 9, 0); // August 15, 2024 09:00
const schedule = scheduleAppointments(firstAppointment, 30, 6); // 6 appointments, 30 min each
console.log(schedule);
// [
//   August 15, 2024 09:00,
//   August 15, 2024 09:30,
//   August 15, 2024 10:00,
//   August 15, 2024 10:30,
//   August 15, 2024 11:00,
//   August 15, 2024 11:30
// ]

Pomodoro Timer

class PomodoroTimer {
  private workMinutes = 25;
  private shortBreakMinutes = 5;
  private longBreakMinutes = 15;
  
  createSession(startTime: Date, cycles: number = 4) {
    const schedule: { type: string, start: Date, end: Date }[] = [];
    let currentTime = new Date(startTime);    

    for (let i = 0; i < cycles; i++) {
      // Work session
      const workEnd = addMinutes(currentTime, this.workMinutes);

      schedule.push({
        type: 'work',
        start: new Date(currentTime),
        end: workEnd
      });
      currentTime = workEnd;
      
      // Break session
      const breakMinutes = (i === cycles - 1) ? this.longBreakMinutes : this.shortBreakMinutes;
      const breakEnd = addMinutes(currentTime, breakMinutes);

      schedule.push({
        type: i === cycles - 1 ? 'long-break' : 'short-break',
        start: new Date(currentTime),
        end: breakEnd
      });
      currentTime = breakEnd;
    }
    
    return schedule;
  }
}

const pomodoro = new PomodoroTimer();
const session = pomodoro.createSession(new Date(2024, 7, 15, 9, 0));
console.log(session);

Immutability

addMinutes() does not modify the original Date object:

const originalDate = new Date(2024, 7, 15, 14, 30);
const modifiedDate = addMinutes(originalDate, 45);

console.log(originalDate);  // August 15, 2024 14:30:00 (unchanged)
console.log(modifiedDate);  // August 15, 2024 15:15:00 (new object)

See Also

• addYears() - Add/subtract years
• addMonths() - Add/subtract months
• addDays() - Add/subtract days
• addHours() - Add/subtract hours
• addSeconds() - Add/subtract seconds
• addMilliseconds() - Add/subtract milliseconds
• subtract() - Calculate differences with Duration objects