A free time zone and sun API

Current time in any IANA zone, every zone's offset right now, sunrise and sunset for any coordinate, moon phase, a DST-correct wall clock converter, and a catalogue of 6,338 cities and 243 countries. No key, no signup, no quota form to fill in. Call it from a browser, a script or a Raspberry Pi.

The base URL is https://dayssincedate.com/api/v1. Every endpoint is a GET, every response is JSON, and every response allows any origin, so you can call this straight from client-side JavaScript without a proxy. There is nothing to install and nothing to register.

Try it now

curl -s "https://dayssincedate.com/api/v1/time/Asia/Tokyo"

const r = await fetch('https://dayssincedate.com/api/v1/convert?from=Europe/London&to=Asia/Kolkata&time=2026-07-04T09:00');
const j = await r.json();
console.log(j.to.iso, j.to.abbreviation, j.differenceText);

What it is built on

Every offset, abbreviation and daylight saving transition is read from the IANA time zone database that ships inside Node, through Intl, at the instant of your request. Nothing here carries a hand-written offset table, because a hand-written table is wrong twice a year in every zone that moves its clocks and permanently wrong in any zone that changes its rules. Sun times use the NOAA solar position algorithm and moon times use the Meeus lunar theory, both of which the site's own 90,645 pages are built on: the API and the page for the same city are computed by the same functions and cannot disagree.

Half-hour and 45-minute zones are handled properly. Kathmandu is UTC+05:45, Adelaide is UTC+09:30 or UTC+10:30 depending on the month, and Chatham Islands is UTC+12:45 or UTC+13:45. Polar day and polar night return nulls with a polar flag rather than a fabricated sunrise. Wall clock readings that never happened, or happened twice, are labelled as such instead of being quietly resolved.

Endpoints

Current time in a zone

GET /api/v1/time/{zone}

The clock in one IANA zone right now: the local ISO string with its offset, the epoch, the abbreviation actually in force, whether daylight saving is on, and the next time the zone changes its offset.

Parameter	Meaning
{zone}	An IANA identifier (`America/New_York`), the slug form (`america-new-york`), or an abbreviation this site publishes pages for (`est`, `pst`, `ist`). An abbreviation names the zone, not the winter offset: `est` answers as Eastern Time and returns EDT in July.

Live response from /api/v1/time/Asia/Kathmandu, status 200:

{
  "zone": "Asia/Kathmandu",
  "abbreviation": "NPT",
  "datetime": "2026-09-25T19:12:49.059+05:45",
  "utcDatetime": "2026-09-25T13:27:49.059Z",
  "epochMs": 1790342869059,
  "unixtime": 1790342869,
  "utcOffset": "+05:45",
  "utcOffsetMinutes": 345,
  "utcOffsetLabel": "UTC+5:45",
  "date": "2026-09-25",
  "time": "19:12:49",
  "dayOfWeek": 5,
  "dayOfWeekName": "Friday",
  "dayOfYear": 268,
  "weekNumber": 39,
  "dst": {
    "observedThisYear": false,
    "active": false,
    "standardOffsetMinutes": 345,
    "savingMinutes": 0
  },
  "nextTransition": null,
  "meta": {
    "generatedAt": "2026-09-25T13:27:49.060Z",
    "docs": "https://dayssincedate.com/api",
    "source": {
      "name": "IANA Time Zone Database",
      "url": "https://www.iana.org/time-zones",
      "licence": "Public domain",
  ... 4 more lines

Every zone and its current offset

GET /api/v1/zones

All 419 published IANA zones with the offset each is on at this moment, in one response, so a client can populate a picker with a single call. Filter by offset to find everyone currently reading the same clock.

Parameter	Meaning
offset	Optional. `+05:45`, `-4` or `-240`. Colons mean hours and minutes; a bare number of 14 or less means hours, anything larger means minutes.
limit	Optional, default and maximum 500.
skip	Optional. Rows to skip, for paging.

Live response from /api/v1/zones?offset=%2B05%3A45, status 200:

{
  "total": 1,
  "count": 1,
  "limit": 500,
  "skip": 0,
  "filter": {
    "utcOffsetMinutes": 345,
    "utcOffset": "+05:45"
  },
  "zones": [
    {
      "zone": "Asia/Kathmandu",
      "utcOffset": "+05:45",
      "utcOffsetMinutes": 345,
      "abbreviation": "NPT"
    }
  ],
  "meta": {
    "generatedAt": "2026-09-25T13:27:49.065Z",
    "docs": "https://dayssincedate.com/api",
    "source": {
      "name": "IANA Time Zone Database",
      "url": "https://www.iana.org/time-zones",
      "licence": "Public domain",
      "credit": "Time zone rules from the IANA database, read through Intl at the instant of the request."
    }
  }
}

One city

GET /api/v1/city/{slug}

A city from the 6,338 row catalogue: coordinates, country, zone, the clock there now, and the full solar day, twilight bands and golden hour included.

Parameter	Meaning
{slug}	A catalogue slug, for example `london`, `new-york`, `munich-germany`. Find one with the cities endpoint below.

Live response from /api/v1/city/reykjavik, status 200:

{
  "city": {
    "slug": "reykjavik",
    "name": "Reykjavik",
    "label": "Reykjavik, Iceland",
    "region": "Capital Region",
    "country": "Iceland",
    "countryCode": "IS",
    "latitude": 64.1466,
    "longitude": -21.9426,
    "population": 118918,
    "timeZone": "Atlantic/Reykjavik",
    "hemisphere": "northern"
  },
  "time": {
    "zone": "Atlantic/Reykjavik",
    "abbreviation": "GMT",
    "datetime": "2026-09-25T13:27:49.065+00:00",
    "utcDatetime": "2026-09-25T13:27:49.065Z",
    "epochMs": 1790342869065,
    "unixtime": 1790342869,
    "utcOffset": "+00:00",
    "utcOffsetMinutes": 0,
    "utcOffsetLabel": "UTC+0",
    "date": "2026-09-25",
    "time": "13:27:49",
    "dayOfWeek": 5,
    "dayOfWeekName": "Friday",
    "dayOfYear": 268,
    "weekNumber": 39,
  ... 138 more lines

Search the city catalogue

GET /api/v1/cities

Search and filter 6,338 cities. Results are ranked by exact name first, then name prefix, then anywhere in the label, with population breaking ties inside each band. So "york" returns York before New York, and "new" returns New York first.

Parameter	Meaning
q	Optional. A name fragment, 60 characters or fewer. Accents and punctuation are ignored.
country	Optional. A country name, its slug, or its ISO 3166-1 alpha-2 code.
limit	Optional, default 25, maximum 100.
skip	Optional. Rows to skip, for paging.

Live response from /api/v1/cities?q=york&limit=3, status 200:

{
  "query": {
    "q": "york",
    "country": null
  },
  "total": 3,
  "count": 3,
  "limit": 3,
  "skip": 0,
  "cities": [
    {
      "slug": "york",
      "name": "York",
      "label": "York, United Kingdom",
      "region": "England",
      "country": "United Kingdom",
      "countryCode": "GB",
      "latitude": 53.9576,
      "longitude": -1.0827,
      "population": 156135,
      "timeZone": "Europe/London",
      "hemisphere": "northern"
    },
    {
      "slug": "new-york",
      "name": "New York",
      "label": "New York, NY",
      "region": "NY",
      "country": "United States",
      "countryCode": "US",
  ... 34 more lines

Convert a wall clock between zones

GET /api/v1/convert

Take a clock reading written in one zone and read it in another, with both offsets resolved at that instant rather than today. The example is 1:30am on the morning the United States falls back, a reading that happens twice, which is why the response says so.

Parameter	Meaning
from	Required. The zone the reading is written in.
to	Required. The zone to read it in.
time	Optional, defaults to now in `from`. A bare wall clock, `YYYY-MM-DDTHH:MM`. A space may replace the T and seconds are accepted and ignored. An offset or a Z is rejected: a string carrying its own offset is already an instant and does not need converting.

Live response from /api/v1/convert?from=America/New_York&to=Australia/Adelaide&time=2026-11-01T01%3A30, status 200:

{
  "from": {
    "zone": "America/New_York",
    "requested": "2026-11-01T01:30",
    "iso": "2026-11-01T01:30:00-04:00",
    "utcOffset": "-04:00",
    "utcOffsetMinutes": -240,
    "abbreviation": "EDT"
  },
  "to": {
    "zone": "Australia/Adelaide",
    "iso": "2026-11-01T16:00:00+10:30",
    "utcOffset": "+10:30",
    "utcOffsetMinutes": 630,
    "abbreviation": "ACDT"
  },
  "utc": "2026-11-01T05:30:00.000Z",
  "epochMs": 1793511000000,
  "differenceMinutes": 870,
  "differenceText": "14 hours 30 minutes",
  "dayShift": 0,
  "wallClock": "ambiguous",
  "usedNow": false,
  "meta": {
    "generatedAt": "2026-09-25T13:27:49.080Z",
    "docs": "https://dayssincedate.com/api",
    "source": {
      "name": "IANA Time Zone Database",
      "url": "https://www.iana.org/time-zones",
      "licence": "Public domain",
  ... 4 more lines

Sun times for a coordinate

GET /api/v1/sun

Sunrise, sunset, solar noon, day length, the three twilight bands, golden hour and blue hour. Nulls are real answers: above the Arctic circle in June there is no sunrise, and the response says polar day rather than inventing one.

Parameter	Meaning
lat	Required. Degrees, north positive, -90 to 90.
lon	Required. Degrees, east positive, -180 to 180.
tz	Optional, defaults to `Etc/UTC`. The zone the returned clock readings are in. There is no coordinate to zone lookup here: use the city endpoint if you want one done for you.
date	Optional, defaults to today in `tz`. `YYYY-MM-DD`, between 1900 and 2100.

Live response from /api/v1/sun?lat=78.22&lon=15.63&tz=Arctic/Longyearbyen&date=2026-06-21, status 200:

{
  "location": {
    "latitude": 78.22,
    "longitude": 15.63,
    "timeZone": "Arctic/Longyearbyen"
  },
  "sun": {
    "date": "2026-06-21",
    "sunrise": null,
    "sunset": null,
    "solarNoon": {
      "iso": "2026-06-21T12:59:17+02:00",
      "epochMs": 1782039557707
    },
    "dayLength": {
      "ms": 86400000,
      "seconds": 86400,
      "text": "24 hours"
    },
    "polar": "day",
    "twilight": {
      "civil": {
        "dawn": null,
        "dusk": null
      },
      "nautical": {
        "dawn": null,
        "dusk": null
      },
      "astronomical": {
  ... 41 more lines

Moon times and phase

GET /api/v1/moon

Moonrise, moonset, the phase name, the lit fraction and the moon age, plus its altitude and azimuth. Moonrise and moonset can each be null on a real day, because the moon rises about fifty minutes later each day and some days it does not manage it before midnight.

Parameter	Meaning
lat	Required. Degrees, north positive.
lon	Required. Degrees, east positive.
tz	Optional, defaults to `Etc/UTC`.
date	Optional, defaults to today in `tz`.

Live response from /api/v1/moon?lat=-33.87&lon=151.21&tz=Australia/Sydney, status 200:

{
  "location": {
    "latitude": -33.87,
    "longitude": 151.21,
    "timeZone": "Australia/Sydney"
  },
  "date": "2026-09-25",
  "moonrise": {
    "iso": "2026-09-25T16:27:20+10:00",
    "epochMs": 1790317640488
  },
  "moonset": {
    "iso": "2026-09-25T04:39:13+10:00",
    "epochMs": 1790275153923
  },
  "additionalRises": [],
  "additionalSets": [],
  "alwaysUp": false,
  "alwaysDown": false,
  "phase": {
    "name": "waxing gibbous",
    "illuminationPercent": 97.02,
    "fraction": 0.97017,
    "ageDays": 13.94,
    "waxing": true,
    "phaseAngle": 19.891,
    "distanceKm": 386340.5
  },
  "position": {
    "altitude": -45.702,
  ... 17 more lines

Every country

GET /api/v1/countries

Every country and territory with its capital, its full zone list and the time in its main zone right now. Useful for anything that needs to turn a country into a clock.

Parameter	Meaning
continent	Optional. `Africa`, `Asia`, `Europe`, `North America`, `South America`, `Oceania` or `Antarctica`.
limit	Optional, default and maximum 300.
skip	Optional. Rows to skip, for paging.

Live response from /api/v1/countries?continent=Oceania&limit=3, status 200:

{
  "total": 27,
  "count": 3,
  "limit": 3,
  "skip": 0,
  "filter": {
    "continent": "Oceania"
  },
  "countries": [
    {
      "name": "American Samoa",
      "slug": "american-samoa",
      "iso2": "AS",
      "continent": "Oceania",
      "capital": "Pago Pago",
      "population": 44000,
      "timeZone": "Pacific/Pago_Pago",
      "timeZones": [
        "Pacific/Pago_Pago"
      ],
      "zoneCount": 1,
      "currentTime": {
        "iso": "2026-09-25T02:27:49-11:00",
        "date": "2026-09-25",
        "time": "02:27",
        "utcOffset": "-11:00",
        "utcOffsetMinutes": -660,
        "abbreviation": "UTC-11"
      }
    },
  ... 65 more lines

Errors

Every failure has the same shape, carries a machine-readable code, a human message, and the correct HTTP status. An error is never returned inside a 200, and a stack trace is never returned at all.

{
  "error": {
    "code": "unknown_zone",
    "status": 404,
    "message": "\"Mars/Olympus_Mons\" is not a time zone this API knows.",
    "parameter": "zone",
    "got": "Mars/Olympus_Mons"
  },
  "meta": {
    "docs": "https://dayssincedate.com/api"
  }
}

Code	Status	When
invalid_parameter	400	A parameter was present but unusable: a latitude of 200, a malformed date, a non-numeric limit.
missing_parameter	400	A required parameter was absent, for example `from` on the convert endpoint.
unknown_zone	404	The zone is not an identifier, slug or abbreviation this API knows.
unknown_city	404	No city in the catalogue has that slug.
not_found	404	The path names no endpoint. The response lists the ones that exist.
method_not_allowed	405	Anything other than GET, HEAD or OPTIONS. This API is read only.
rate_limited	429	Over the limit below. The response carries `Retry-After`.
internal_error	500	Something broke here. The detail is in our logs, not in your response.

Rate limit

60 requests per minute per IP address, as a fixed window. Every response tells you where you stand:

X-RateLimit-Limit: 60, the ceiling for the window.
X-RateLimit-Remaining: how many you have left in this window.
X-RateLimit-Reset: the Unix second the window resets at.

Go over and you get a 429 with a Retry-After header in seconds. Preflight OPTIONS requests are answered but not counted, so a browser client does not spend half its quota on the browser's own behalf.

If 60 a minute is not enough, the answer is almost always caching rather than asking for more. Every response carries a Cache-Control header: five seconds for a clock reading, until the next UTC midnight for anything keyed on today, and a full day for a sun or moon request with an explicit date, because that answer is a property of the date and will never change. Honour those and a busy client makes a handful of calls an hour.

Licence and attribution

This is the part that is a condition, not a courtesy. If you publish anything built on these responses, you have to pass the credit on.

City data: coordinates, population, region and time zone for all 6,338 cities come from GeoNames (cities15000), licensed CC BY 4.0. Any response carrying a city row also carries meta.attribution naming it. If you display that data, display the credit.
Weather data: the site's own pages use forecasts from MET Norway, licensed CC BY 4.0. No endpoint on this API serves weather, so nothing you fetch here carries that obligation, but the credit is stated here because the data is on the site you are reading.
Time zone rules: the IANA time zone database, which is in the public domain.
Everything else: the computed output is free to use, commercially included. A link back is welcome and is the only thing keeping this free, but it is not required.

There is no SLA

Being honest about this is more useful to you than a promise would be. This API runs on one small server alongside the rest of the site. There is no uptime guarantee, no support contract, no status page and no paid tier to escalate to. It has been stable and it is intended to stay that way, and the /v1 in the path is a real commitment that these response shapes will not change underneath you: new fields may be added, existing ones will not be removed or repurposed inside v1. But if your product would be broken by this endpoint being unreachable for an afternoon, cache the responses or run your own copy of the maths. Do not build a paging system on it.

If something is wrong, or you need an endpoint that is not here, the site has contact details on its about page.