A Prayer Reminder App with Zero API Cost

Two endpoints on API.MY.ID are completely free and need no API key: prayer times and national holidays. No quota, no points, no signup. This article builds a simple prayer reminder app on top of them.

The first call

No headers, no auth — just a GET:

curl "https://v1.api.my.id/sholat?city=jakarta"

{
  "status": "success",
  "data": {
    "city": { "slug": "jakarta", "name": "Jakarta" },
    "date": "2026-07-09",
    "timezone": "WIB",
    "jadwal": {
      "imsak": "04:31", "subuh": "04:41", "terbit": "06:04", "dhuha": "06:28",
      "dzuhur": "12:00", "ashar": "15:20", "maghrib": "17:53", "isya": "19:06"
    }
  }
}

How the times are computed

Prayer times are not rows in a table — they are computed from the sun's position for the requested coordinates and date. We use the angle conventions commonly used by Kemenag: Fajr at −20°, Isha at −18°, sunrise and maghrib at −0.833° (accounting for atmospheric refraction and the solar radius), and Asr by the Shafi'i method. A +2 minute ihtiyat (safety margin) is added to Dhuhr and Maghrib.

The practical upshot: 54 cities are supported with correct time zones (WIB, WITA, WIT), and you can request any date — yesterday, today, or Ramadan next year.

Scheduling notifications

The right pattern: fetch the schedule once a day, then schedule local notifications. Do not poll the API every minute — the schedule does not change.

const PRAYERS = ['subuh', 'dzuhur', 'ashar', 'maghrib', 'isya'];

async function scheduleToday(city = 'jakarta') {
  const res = await fetch(`https://v1.api.my.id/sholat?city=${city}`);
  const { data } = await res.json();

  for (const name of PRAYERS) {
    const [h, m] = data.jadwal[name].split(':').map(Number);
    const at = new Date();
    at.setHours(h, m, 0, 0);

    const delay = at - Date.now();
    if (delay <= 0) continue;               // already passed today

    setTimeout(() => {
      new Notification(`Time for ${name}`, {
        body: `${data.jadwal[name]} ${data.timezone} — ${data.city.name}`,
      });
    }, delay);
  }
}

// run on app open, and at midnight
scheduleToday();

Ramadan: imsak and iftar

For sahur and iftar timers, the two fields you need are already in the same response: imsak and maghrib. Since you can request any date, the whole Ramadan calendar can be fetched once and cached locally:

async function ramadanCalendar(city, start, days = 30) {
  const out = [];
  for (let i = 0; i < days; i++) {
    const t = new Date(start);
    t.setDate(t.getDate() + i);
    const date = t.toISOString().slice(0, 10);

    const res = await fetch(`https://v1.api.my.id/sholat?city=${city}&date=${date}`);
    const { data } = await res.json();
    out.push({ date, imsak: data.jadwal.imsak, iftar: data.jadwal.maghrib });
  }
  return out;   // persist to localStorage / SQLite
}

Bonus: the holiday calendar

The second free endpoint rounds out any calendar app. It returns national holidays and joint-leave days per the official SKB decree, with flags distinguishing the two:

curl "https://v1.api.my.id/holidays/upcoming?limit=3"

Because both are free and keyless, this entire app can run with no backend at all — call them straight from the client. This is the one case where we recommend that, precisely because there is no key to leak.