{"slug":"when-did-the-us-stock-market-start","qid":"weekday_sessions","label":"Trading sessions by day of the week, calendar year 2019","post_title":"When Did the US Stock Market Start? 1792","post_url":"/blog/when-did-the-us-stock-market-start#q-weekday_sessions","columns":["weekday","trading_days","calendar_days"],"rows":[{"weekday":"Monday","trading_days":48,"calendar_days":52},{"weekday":"Tuesday","trading_days":52,"calendar_days":53},{"weekday":"Wednesday","trading_days":51,"calendar_days":52},{"weekday":"Thursday","trading_days":50,"calendar_days":52},{"weekday":"Friday","trading_days":51,"calendar_days":52},{"weekday":"Saturday","trading_days":0,"calendar_days":52},{"weekday":"Sunday","trading_days":0,"calendar_days":52}],"shape":"series","sql":"SELECT\n    formatDateTime(cal.day, '%W')   AS weekday,\n    countIf(s.sessions > 0)         AS trading_days,\n    count()                         AS calendar_days\nFROM\n(\n    SELECT toDate('2019-01-01') + arrayJoin(range(365)) AS day\n) AS cal\nLEFT JOIN\n(\n    SELECT\n        date     AS d,\n        count()  AS sessions\n    FROM global_markets.stocks_daily_aggs\n    WHERE ticker = 'SPY'\n      AND date >= '2019-01-01'\n      AND date <  '2020-01-01'\n    GROUP BY d\n) AS s ON s.d = cal.day\nGROUP BY weekday\nORDER BY min(toDayOfWeek(cal.day))","computed_at":"2026-08-08T15:40:29.042282+00:00","elapsed":0.083940505}