weekday_onset
Answered against 22 years of US equities and 12 years of US options data and published with the query that produced it. This result is stored as of 2026-10-01, from options-expirations-by-weekday.
| month | mondays | tuesdays | wednesdays | thursdays | fridays |
|---|---|---|---|---|---|
| 2021-10 | 4 | 0 | 4 | 0 | 4 |
| 2021-11 | 5 | 0 | 4 | 0 | 4 |
| 2021-12 | 4 | 0 | 5 | 1 | 4 |
| 2022-01 | 4 | 1 | 4 | 0 | 4 |
| 2022-02 | 3 | 1 | 4 | 0 | 4 |
| 2022-03 | 4 | 0 | 5 | 1 | 4 |
| 2022-04 | 4 | 0 | 4 | 1 | 4 |
| 2022-05 | 4 | 1 | 4 | 0 | 4 |
| 2022-06 | 3 | 1 | 5 | 1 | 4 |
| 2022-07 | 3 | 1 | 4 | 0 | 5 |
| 2022-08 | 5 | 0 | 5 | 0 | 4 |
| 2022-09 | 3 | 1 | 4 | 0 | 5 |
| 2022-10 | 5 | 0 | 4 | 0 | 4 |
| 2022-11 | 4 | 3 | 5 | 1 | 4 |
| 2022-12 | 3 | 4 | 4 | 5 | 5 |
| 2023-01 | 3 | 5 | 4 | 4 | 4 |
| 2023-02 | 3 | 4 | 4 | 4 | 4 |
| 2023-03 | 4 | 4 | 5 | 5 | 5 |
| 2023-04 | 4 | 4 | 4 | 4 | 3 |
| 2023-05 | 4 | 5 | 5 | 4 | 4 |
| 2023-06 | 3 | 4 | 4 | 5 | 5 |
| 2023-07 | 5 | 3 | 4 | 4 | 4 |
| 2023-08 | 4 | 5 | 5 | 5 | 4 |
| 2023-09 | 3 | 4 | 4 | 4 | 5 |
| 2023-10 | 5 | 5 | 4 | 4 | 4 |
| 2023-11 | 4 | 4 | 5 | 4 | 4 |
| 2023-12 | 3 | 4 | 4 | 4 | 5 |
| 2024-01 | 3 | 5 | 5 | 4 | 4 |
| 2024-02 | 3 | 4 | 4 | 5 | 4 |
| 2024-03 | 4 | 4 | 4 | 4 | 4 |
| 2024-04 | 5 | 5 | 4 | 4 | 4 |
| 2024-05 | 3 | 4 | 5 | 5 | 5 |
| 2024-06 | 4 | 4 | 3 | 4 | 4 |
| 2024-07 | 5 | 5 | 5 | 3 | 4 |
| 2024-08 | 4 | 4 | 4 | 5 | 5 |
| 2024-09 | 4 | 4 | 4 | 4 | 4 |
| 2024-10 | 4 | 5 | 5 | 5 | 4 |
| 2024-11 | 4 | 4 | 4 | 3 | 5 |
| 2024-12 | 5 | 5 | 3 | 4 | 4 |
| 2025-01 | 3 | 4 | 4 | 5 | 5 |
| 2025-02 | 3 | 4 | 4 | 4 | 4 |
| 2025-03 | 5 | 4 | 4 | 4 | 4 |
| 2025-04 | 4 | 5 | 5 | 4 | 3 |
| 2025-05 | 3 | 4 | 4 | 5 | 5 |
| 2025-06 | 5 | 4 | 4 | 3 | 4 |
| 2025-07 | 4 | 5 | 5 | 5 | 3 |
| 2025-08 | 4 | 4 | 4 | 4 | 5 |
| 2025-09 | 4 | 5 | 4 | 4 | 4 |
| 2025-10 | 4 | 4 | 5 | 5 | 5 |
| 2025-11 | 4 | 4 | 4 | 3 | 4 |
| 2025-12 | 5 | 5 | 5 | 3 | 4 |
| 2026-01 | 3 | 4 | 4 | 4 | 5 |
| 2026-02 | 3 | 4 | 4 | 4 | 4 |
| 2026-03 | 5 | 5 | 4 | 4 | 4 |
| 2026-04 | 4 | 4 | 5 | 5 | 3 |
| 2026-05 | 3 | 4 | 4 | 4 | 5 |
| 2026-06 | 5 | 5 | 4 | 4 | 3 |
| 2026-07 | 4 | 4 | 5 | 5 | 4 |
| 2026-08 | 5 | 4 | 4 | 4 | 4 |
| 2026-09 | 3 | 5 | 5 | 4 | 4 |
- Rows × columns
- 60 × 6
- Computed
- Completeness
- No missing values
- Source
- US exchange, SIP and OPRA market data
- Licence
- Strasmore terms · free, no signup
What each column holds
| Column | Type | Range | Notes |
|---|---|---|---|
month |
text | 60 distinct values (2021-10, 2021-11, 2021-12…) | |
mondays |
number | 3 to 5 | |
tuesdays |
number | 0 to 5 | |
wednesdays |
number | 3 to 5 | |
thursdays |
number | 0 to 5 | |
fridays |
number | 3 to 5 |
Computed from Strasmore's warehouse of US exchange, SIP and OPRA market data. Equity prices are delayed; options greeks and implied volatility are end-of-day. This result is stored, not recomputed on load — it is exactly the numbers that were returned on , and the query below is what returned them.
Run it yourself
This is the exact query behind the result above. Change a ticker, a date or a column and run it against the warehouse — no account, no key. The no-signup tier is smaller than the one this page was computed on; a query that reaches past it comes back saying which plan runs it.
SELECT
formatDateTime(toStartOfMonth(expiration_date), '%Y-%m') AS month,
countDistinctIf(expiration_date, toDayOfWeek(expiration_date) = 1) AS mondays,
countDistinctIf(expiration_date, toDayOfWeek(expiration_date) = 2) AS tuesdays,
countDistinctIf(expiration_date, toDayOfWeek(expiration_date) = 3) AS wednesdays,
countDistinctIf(expiration_date, toDayOfWeek(expiration_date) = 4) AS thursdays,
countDistinctIf(expiration_date, toDayOfWeek(expiration_date) = 5) AS fridays
FROM global_markets.options_greeks
WHERE underlying_symbol = 'SPY'
AND date >= '2021-10-01'
AND date < today()
AND expiration_date >= '2021-10-01'
AND expiration_date < toStartOfMonth(today())
AND volume > 0
GROUP BY month
ORDER BY month
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