The National Stock Exchange (NSE) and BSE will swap their weekly derivatives expiry days starting September 1, after receiving approval from the Securities and Exchange Board of India (Sebi). NSE will move to Tuesday expiries, while BSE will shift to Thursday.The change comes as part of Sebi’s directive to standardize equity derivatives expiries to only two days of the week — Tuesdays or Thursdays — aimed at avoiding congestion at the start or end of the trading week.In circulars issued on Monday, both exchanges confirmed that Sebi had agreed to their proposed expiry day preferences.“Sebi has agreed to the expiry day proposed by NSE i.e. Tuesday,” NSE stated, while BSE also confirmed, “Sebi has agreed to the expiry day proposed by BSE (i.e. Thursday).”The revised expiry schedule will apply to new equity derivatives contracts expiring on or after September 1, 2025, reported PTI. Contracts already introduced — including those set to expire before that date — will continue to follow their current expiry schedules.However, the exchanges clarified that long-dated index options contracts may be realigned to match the new expiry format where necessary.To facilitate a smooth transition, both NSE and BSE are expected to release detailed operational guidelines in the coming weeks.The regulatory shift follows Sebi’s May announcement formalising the expiry framework. The capital markets regulator had first floated the proposal in March through a consultation paper recommending that expiries across exchanges be restricted to Tuesdays or Thursdays, rather than Mondays or Fridays.In response to the consultation, NSE deferred an earlier plan to move all index and stock derivative expiries to Monday — a transition that was initially scheduled for April 4, 2025 — until further notice.Any change in expiry or settlement dates for derivatives contracts will require prior Sebi approval, the regulator said.