Options Expiry Countdown Timer

This options expiry countdown timer calculates rough trading-hour and theta estimates for a selected expiry. It does not display a running countdown. Its displayed trading hours and theta labels are rough estimates, and its clock is not a reliable current exchange deadline. Replace the prefilled custom date with a verified expiry; the automatic date route also needs checking. Nifty has weekly options; Bank Nifty, FinNifty and Midcap Nifty do not have weekly expiries. This page explains the date choices and the limits of each result.

Which expiry should the selector use?

The Select Expiry menu offers Nifty weekly and monthly options; Bank Nifty, FinNifty and Midcap Nifty monthly options; and Sensex weekly options. An expiry is the end date of a particular contract. The regular weekday helps locate it, but a trading holiday can move the contract to an earlier open day.

NSE’s revised Tuesday framework applies to contracts expiring from September 2025 onward, with transition details in its circular. BSE’s corresponding Thursday framework covers contracts expiring after the start of September 2025. These are regular patterns, not a promise that the same weekday is an open trading day every week.

NSE discontinued Bank Nifty, FinNifty and Midcap Nifty weekly contracts in November 2024. A date calculation cannot create a contract that the exchange does not list. Use your broker’s contract details together with the exchange information to identify the exact series.

Nifty, Bank Nifty and Sensex expiry days: the current schedule

The list below is the standing weekday rule for each index. It is checked against the exchange circulars named in the Sources section, and the date of the check is in the caption. If a contract date falls on a trading holiday, the expiry moves to the previous trading day. Always confirm the exact date in your broker's contract list.

Nifty weekly and monthly expiry moved to Tuesday from September 2025. Before that, the weekday was different, and older blog posts still show the old days. Weekly contracts on Bank Nifty, FinNifty and Midcap Nifty were discontinued in November 2024, so there is no weekly Bank Nifty expiry. See weekly vs monthly expiry for how the two differ.

The custom date overrides the menu

The field Or Enter Custom Expiry Date accepts a year-month-day date. When it contains a date in the expected format, the calculation uses that date instead of finding an expiry from the menu. Changing the index while leaving the prefilled custom value in place therefore does not switch the calculation to that index’s next expiry.

Clear that field to use the normal selector route. If you enter your own date, copy a verified contract expiry rather than typing the normal weekday from memory. The custom-date route does not move a holiday date to the previous trading day. The form can also roll an impossible calendar date into another month instead of rejecting it.

Automatic holiday checks use a stored NSE calendar for 2026, even for Sensex. They do not verify BSE holidays or later years.

After an expiry moved earlier for a holiday has passed its cutoff, the automatic route can retain the original holiday date instead. Clearing the custom field alone does not guarantee a valid future expiry.

The tool evaluates dates in the computer’s local time zone. Using it outside India can change the moment it treats as the cutoff. There is no time-zone or closing-time control. A browser clock setting cannot establish an exchange’s official deadline, and a result should not substitute for your broker’s earlier operational cutoff.

What the four visible results mean

• Total Trading Hours: an approximation from elapsed days, a weekday fraction and a stored session length. It does not add up the open minutes of each remaining session.
• Theta Multiplier: a formula based only on days remaining. It does not use the contract’s premium, strike, underlying price or implied volatility.
• Estimated Daily Theta: a message directing you to an options calculator, not a calculated rupee amount.
• Urgency Level: a label based on remaining whole calendar days. It does not measure the risk of your position or tell you whether to trade.

The result cards show the four outputs listed above, without a target-date card or a running days-hours-minutes clock. The figures update when inputs change or you press Calculate. They do not keep ticking while you leave the page open.

This tool has no fields for alerts, messages, broker orders or option quotes. It cannot monitor your positions or close a trade when time runs out. Record the official expiry in your own trading plan and check it independently of the urgency label.

A holiday example with the calculator’s actual estimate

NSE’s holiday notice lists Tuesday 20 Oct 2026 as Dussehra. Under the previous-trading-day rule, the affected Nifty weekly expiry falls on Monday 19 Oct 2026. This is a useful check because a simple “next Tuesday” assumption would point to a closed market day.

For a fixed illustrative check, assume it is 15:30 on 15 Oct 2026 with the computer set to India time. This matches the tool’s built-in cutoff. Select Nifty Weekly and leave the custom field empty. The selected target is 19 Oct, giving 19 - 15 = 4 full calendar days to the tool’s cutoff.

The formula converts that interval into 2 assumed trading days and displays 12.5 Total Trading Hours. Its Theta Multiplier is 0.5x and Urgency Level is MODERATE. These reproduce the existing formula; the 12.5-hour figure is not an exact count of remaining open-market time. It loses the actual weekday pattern, uses the old session duration and does not reflect the revised exchange close.

If you type the holiday itself into the custom field, the override keeps that date instead. That explains why the same index selection can yield different results with and without a custom date. For a separate calendar-day check, see the trading days calculator and read its boundary and holiday assumptions.

Upcoming expiry dates, with holiday shifts

Using the standing rules and the 2026 NSE trading holidays kept in this site's expiry rules, the next dates are below. Two holidays fall on Tuesdays in November 2026, so those Nifty expiries move one trading day earlier.

The rule is simple. If the usual day is a closed market day, use the last open day before it. That is why a plain 'next Tuesday' guess can be wrong. Because the Nifty monthly expiry is the last Tuesday of the month, a holiday on that Tuesday moves the monthly contract as well as the weekly one.

What time do Nifty options expire?

Nifty options stop trading at the close of the derivatives session on expiry day. NSE changed the derivatives close to 15:40 IST from 3 Aug 2026 in circular NSE/FAOP/74467. The older 15:30 close no longer applies to F&O. The cash market can have different timings, including a closing auction for some stocks, so do not copy one close time across all products.

The final settlement price of an index option is based on the closing value of the index on the last trading day, as NSE's settlement pages describe. This timer uses an older close and your device's time zone, so use it only for a rough sense of time left. Your broker may also stop accepting some orders or square-off positions earlier than the exchange, so check their cut-off.

Time left is not a forecast of premium loss

Theta means the theoretical change in an option’s premium as time passes with other pricing factors held constant. The Options Industry Council explains that time decay is not linear and pricing models can handle it differently. Actual option prices also change as the underlying and expected volatility change.

This timer has no contract-specific pricing inputs. Its multiplier therefore cannot tell you how many rupees an option will lose overnight or how much a seller will earn. A lower remaining-day count also does not establish that an option will expire worthless. Read theta decay before interpreting any time-based label as an option-value estimate.

The theta decay calculator explores separate entered assumptions; its estimates also need their own limits. For broader date checks, the expiry day calculator provides another reference. Neither a date estimate nor a premium model places an order or satisfies an expiry obligation.

What happens to your option at expiry

If you do nothing, the contract settles by the exchange's rules. For Nifty and other index options, NSE's settlement pages describe cash settlement. That means no shares change hands. In-the-money options at the close are exercised automatically, and the gain or loss is settled in cash through the clearing accounts, normally on the next working day. NSE's index options are European style, so exercise happens only at expiry. One NSE page for Nifty 50 options describes settlement as physical, which conflicts with the settlement pages, so check both and your broker's note.

• Out-of-the-money option you bought: it expires worthless and you lose the premium paid.
• In-the-money option you bought: it is exercised automatically and settled in cash. Buyers whose options are exercised pay securities transaction tax (STT) on the intrinsic value, at 0.15% since 1 Apr 2026 per NSE/FATAX/73524. Selling before expiry can cost less in tax, but you should compare with your own contract note.
• Option you sold: you must pay the settlement amount if it ends in the money, and the loss can exceed the premium received.
• Stock options: these follow separate rules, and delivery-based settlement can apply. Read NSE's settlement mechanism page before holding a stock option into expiry.

So, what if you do not close your option before expiry? An out-of-the-money long option lapses. An in-the-money one is settled for you, which may bring a cash credit and a tax charge. A short option that ends in the money can mean a large debit. Many traders close or manage positions before the last hour so that settlement is not a surprise.

Expiry-day rules to follow

These are habits some traders write into their plans. They are not signals or advice.

• Know the exact expiry date and cut-off time before entering. Do not rely on memory of the weekday.
• Remember that time decay (theta) speeds up near expiry, and option prices can change quickly in the last hours.
• Keep position size smaller than usual, because small index moves can change an option's value a lot on the last day.
• Decide the exit before you enter. On expiry day moves are fast, and a written plan is easier to follow than a quick decision.
• Do not trade every expiry out of habit. Skipping a day is a valid choice.
• After the day, log what you did and whether you followed your plan. Read expiry day trading and weekly expiry for more.

OneTradeJournal logs trades by hand and does not send alerts, so write the expiry date and your exit plan in the trade's notes.

Questions about the expiry timer

Sources

• NSE/FAOP/68747: revised expiry weekdays; checked 15 Oct 2026.
• NSE/FAOP/64506: discontinued weekly index contracts; checked 15 Oct 2026.
• BSE notice 20250623-59: revised Thursday expiries; checked 15 Oct 2026.
• NSE/FAOP/71777: trading holidays; checked 15 Oct 2026.
• NSE/FAOP/74467: revised equity derivatives close and current NSE timings; checked 15 Oct 2026.
• OIC: theta and time decay; checked 15 Oct 2026.
• NSE: Nifty expiry and previous-trading-day rule; checked 15 Oct 2026.