Service metadata

Code snippets

curl "https://api.oanor.com/calendareffects-api/v1/meta" \
  -H "x-oanor-key: oanor_test_..."

await fetch("https://api.oanor.com/calendareffects-api/v1/meta", {
  headers: { "x-oanor-key": "oanor_test_..." }
});

$ch = curl_init("https://api.oanor.com/calendareffects-api/v1/meta");
curl_setopt($ch, CURLOPT_HTTPHEADER, ["x-oanor-key: oanor_test_..."]);
curl_setopt($ch, CURLOPT_RETURNTRANSFER, true);
$out = curl_exec($ch);

import requests
requests.get(
    "https://api.oanor.com/calendareffects-api/v1/meta",
    headers={"x-oanor-key": "oanor_test_..."}
)

Example response

A real response from this endpoint, captured by the latest health check.

{
    "data": {
        "note": "symbol is a universe symbol (SPY, GLD, BTC-USD, ...). window is 252-3000 trading days (default 1260, ~5 years, for robust calendar stats). class filters the screener to index/sector/commodity/bond/crypto (default all). Month-of-year seasonality is covered by the seasonality APIs; this is day-of-week and turn-of-month. Read fresh per call, nothing cached.",
        "source": "Yahoo Finance daily closes, live",
        "classes": [
            "index",
            "sector",
            "commodity",
            "bond",
            "crypto"
        ],
        "service": "calendareffects-api",
        "universe": [
            "SPY",
            "QQQ",
            "IWM",
            "EFA",
            "EEM",
            "XLK",
            "XLF",
            "XLE",
            "XLU",
            "GLD",
            "SLV",
            "USO",
            "DBC",
            "TLT",
            "HYG",
            "BTC-USD",
            "ETH-USD"
        ],
        "endpoints": {
            "GET /v1/meta": "This document.",
            "GET /v1/screener": "Rank the universe by turn-of-month effect strength (window=1260, class=all).",
            "GET /v1/dayofweek": "Average return and win-rate by weekday for one instrument (symbol=SPY, window=1260).",
            "GET /v1/turnofmonth": "Turn-of-month vs rest-of-month return profile for one instrument (symbol=SPY, window=1260)."
        },
        "description": "Calendar effects — day-of-week & turn-of-month — the two best-documented equity calendar anomalies, measured live across a cross-asset universe from Yahoo Finance daily history (no key, nothing stored). turnofmonth splits an instrument's history into the turn-of-month window (last 1 + first 3 trading days of each month) versus the rest and returns each side's average daily return, win-rate, the spread, and the share of total return earned in the turn days. dayofweek returns each weekday's average return, win-rate and sample size with the best/worst day. screener ranks the universe by the strength of the turn-of-month effect. The day-of-week / turn-of-month calendar-anomaly cut — distinct from the month-of-year seasonality APIs (equity-index, FX, commodity) and the crypto-only intraday/day-of-week seasonality API. Descriptive, not predictive.",
        "universe_size": 17,
        "upstream_status": "ok",
        "turn_of_month_window": "last 1 + first 3 trading days of each month",
        "strongest_turn_of_month": "EEM"
    },
    "meta": {
        "timestamp": "2026-06-12T10:34:39.954Z",
        "request_id": "3d7e836a-a693-4902-a95d-ef24853d56d8"
    },
    "status": "ok",
    "message": "Meta",
    "success": true
}