Educational only, not financial advice or a strategy recommendation. Options strategies carry risk, including of substantial loss. The strategies here are explained for understanding, not endorsed.
A calendar spread sells a near-dated option and buys a longer-dated one to profit from differing time decay, which makes a pure 0DTE calendar awkward. See the general calendar spread explainer for full mechanics.
How calendars work
You sell the front (near) expiration and buy a back (later) expiration at the same strike. The near option decays faster than the far one, so the spread profits from that decay differential if the underlying stays near the strike. It’s a play on time and volatility, not pure direction — and it depends on two different expirations.
The 0DTE angle
A calendar using a 0DTE as the short leg (selling today’s expiration) against a longer-dated long leg is a real structure — you harvest the 0DTE’s ferocious decay while holding a slower-decaying long option. But it’s not a “0DTE strategy” in the scalping sense; it’s a two-expiration position, more of a swing/income structure than an intraday scalp. And it carries assignment and management complexity.
A calendar needs two expirations, so “pure 0DTE calendar” is a contradiction — but selling a 0DTE against a longer option to harvest fast decay is a real, if non-scalping, play.
Where the dealer map fits
NoVo maps intraday dealer structure on SPY, QQQ and IWM — the levels that matter inside a single session, not across two expirations. Calendars are a valid income/swing structure, a different discipline. Related: the diagonal (a calendar with different strikes).