npm install @danepliz/nepali-calendar

<input type=text id="calendar">

import NepaliCalendar from '@danepliz/nepali-calendar'

let element = document.getElementById('claendar')
calendar = new NepaliCalendar(element, {
    path: '/nepali-calendar.json', // path to calendar data
    onChange: (date) => {}, // called on date select
})

valid json for calendar data

{
  "2081": [
    [1, "2024-04-14", 30],
    [2, "2024-05-14", 31],
    [3, "2024-06-14", 31],
    [4, "2024-07-15", 31],
    [5, "2024-08-15", 30],
    [6, "2024-09-14", 30],
    [7, "2024-10-14", 30],
    [8, "2024-11-13", 29],
    [9, "2024-12-12", 29],
    [10, "2025-01-11", 30],
    [11, "2025-02-10", 30],
    [12, "2025-03-11", 30]
  ],
  "2082": [
    [1, "2025-04-14", 31],
    [2, "2025-05-15", 31],
    [3, "2025-06-15", 32],
    [4, "2025-07-17", 31],
    [5, "2025-08-17", 31],
    [6, "2025-09-17", 31],
    [7, "2025-10-18", 30],
    [8, "2025-11-17", 29],
    [9, "2025-12-16", 30],
    [10, "2026-01-15", 39],
    [11, "2026-02-13", 30],
    [12, "2026-03-15", 30]
  ],
  "2083": [
    [1, "2026-04-08", 30],
    [2, "2026-05-08", 31],
    [3, "2026-06-08", 31],
    [4, "2026-07-09", 31],
    [5, "2026-08-09", 30],
    [6, "2026-09-08", 30],
    [7, "2026-10-08", 30],
    [8, "2026-11-07", 29],
    [9, "2026-12-06", 29],
    [10, "2027-01-05", 30],
    [11, "2027-02-04", 30],
    [12, "2027-03-05", 30]
  ]
}