A company event can be dated by its occurrence, by the publication time of the company's announcement, by the time a regulator accepted the filing or by the time a feed first saw it. This post sets out the convention behind each date and which one a back-test or an alert should use. It then shows how to measure a feed's delay on a sample of your own, and which evidence lets you verify an event at its source.
Is a company event dated by its occurrence date or its publication time?
A company event carries up to four dates, and a good record keeps them apart. The occurrence date is when the event happened, and the publication time is when the company made it public. A filing adds the time the regulator accepted it; a feed adds the time it first held the item.
Errors come from the gaps between them. An agreement signed on a Friday can be announced on the Monday, filed later that week and picked up by a feed after that. A test dated by the occurrence can act before anyone outside the company could know, which is look-ahead bias.
| Date | What it records | Who sets it | Use it for |
|---|---|---|---|
| Occurrence date | The day the event happened | The company, in its own text; on a current report, the date of report on the cover | Research on the event itself |
| Publication time | When the company made the announcement public, on its newsroom or in its feed | The company | An alert's clock, and the earliest a back-test may act on an announcement |
| Filing date and accepted time | When the regulator's system accepted the filing, and the business day it counts as filed | EDGAR, under the SEC's rules | The moment a filing became public record |
| First-seen time | When a feed, or your own copy of it, first held the item | The feed, or your own load | Back-tests run on that feed, and the feed's delay |
Feeds can add a fifth time that fits none of these roles. The Atom feed format, published by the IETF as RFC 4287, requires exactly one updated time on every entry and allows at most one published time. The updated time marks the latest change the publisher considers significant, and the publisher may change it over time. The published time, when present, is typically when the entry was created or first made available. An event dated by the updated time is dated by its latest significant edit.
How the SEC dates a current report
For a listed company in the United States, the official record of many events is a current report on Form 8-K. The SEC's own pages fix three of its dates: the event, the deadline and the filing.
The deadline. The SEC's page on Exchange Act reporting and registration, among its resources for small businesses, says a company must file current reports on Form 8-K to report specified events, often within four business days after the event occurs. The events it lists include entering into or terminating a material definitive agreement, completing an acquisition or disposition of assets, a change in control, the election of directors and the appointment or departure of principal officers.
How the four days are counted. The Division of Corporation Finance staff's interpretations of Form 8-K show the count for one item, the results of a shareholder vote. Day one is the day after the meeting ends, so a meeting that ends on a Tuesday starts the count on the Wednesday and the period ends on the Monday. In that case six calendar days separate the event from the last day of a filing that is on time.
The date of the event on the cover. The cover of a current report carries its date of report, which is the date of the earliest event reported. In a 2020 announcement on structured data, SEC staff noted that some filers had tagged the filing date, or a date unrelated to the event, as the period end date of a current report, and said the tag should carry the date of report shown on the cover. Read the cover, and check any structured date against it.
The filing date and the accepted time. The SEC's filer support guide on the status of a filing says a submission is not an official filing unless its acceptance message includes a filing date. A live submission that begins transmission at or before 5:30 pm Eastern Time on a day EDGAR operates, and is accepted, receives that day's filing date. Most that begin after 5:30 pm receive a filing date of 6:00 am Eastern Time on the next business day and are not disseminated until that day. EDGAR accepts filings each business day, Monday to Friday, from 6:00 am to 10:00 pm Eastern Time.
The accession number. EDGAR's guide to accessing its data describes the accession number as a unique identifier assigned automatically to an accepted submission. Its first group of digits is the CIK of the entity that submitted the filing, which can be the company or a third-party filer agent; the next two give the year, and the rest count that submitter's filings in sequence. So the first part is not always the company's Central Index Key.
A filing's index page on EDGAR brings these together: the filing date, the accepted time to the second, the period of report, the items a current report was filed under and the accession number.
Which date should a back-test or an alert use?
Use the first moment the information could have reached you, which depends on what the test runs on. The occurrence date belongs to research on the event, never to the timing of a trade.
- A back-test on announcements. Take the publication time with the time zone the company states. A page that gives a date and no time gives the whole day, so assume the end of it.
- A back-test on filings. Take the accepted time, or the filing date where that is later: for most submissions begun after 5:30 pm Eastern Time, 6:00 am on the next business day.
- A back-test on a vendor's feed. Take the time each item reached your copy. A dataset dated by publication time lets a test act on items not yet received, so add the delay you measured.
- An alert. Trigger on arrival, show the publication time, and remove duplicates on a stable key: the accession number for a filing, the address of the original for a newsroom item. A press release and a filing about the same event are two records of it, each with its own date.
The guide to building company change alerts covers alerts, and the entry on point-in-time data the record a test needs.
The date on an announcement in our data
The Company News dataset dates each announcement by when the company published it. Where the source gives no date, the record carries the time we first saw the item. An announcement is something the company said about itself in public: an item on its newsroom or press page, an entry in its own news feed or, for a listed company, a regulatory disclosure.
Every record carries the evidence to check it:
- the title as published;
- an excerpt of the company's own text, at most 1,200 characters;
- the address of the original announcement or filing document;
- its event types, from 13 kinds;
- for a regulatory disclosure, the item numbers it was filed under and its accession number;
- for a leadership change, the role concerned, such as chief financial officer or board, and never the person.
The data dictionary defines each field and each event type.
How quickly does a company signal feed pick up a new announcement?
A company signal feed picks up a new announcement as fast as it reads the source and delivers what it found, and a measurement on your own sample settles how fast that is. One item's delay is the time it first reached your copy minus the time the company published it.
Five things set the delay.
- How often the source is read, against the refresh cadence the vendor states for the dataset: see data freshness.
- How often you pull. Pulled hourly, an item logged at 10:00 arrived after 09:00.
- The filing calendar. A filing begun after 5:30 pm Eastern Time usually takes the next business day's filing date.
- Weekends, at the company, at the feed or at your end.
- What the page states. A date with no time can be measured to the day and no closer.
Company news and announcement feed latency: press releases, RSS and real time
Latency in a company news feed is the gap between a press release going live and the feed delivering it to you. The company's newsroom or its RSS or Atom feed gives the start of the clock, and your own log of arrivals gives the end. Treat real time as a claim to measure on a sample.
Take the start of the clock from the company's own page or from the entry's published time, never from its updated time. A record dated by when it was first seen, because its source gave no date, hides the feed's own delay by construction: leave such records out of the measurement and count them apart. Convert every time to one zone before you subtract.
Example: measuring a feed's delay on a sample
This example is illustrative. Acme Robotics is an invented company, the feed under test is any feed, and every figure below is an assumption, not a measurement of any dataset.
Assumptions:
- Between Monday 2 March and Monday 9 March 2026, Acme Robotics makes six announcements: five on its newsroom and one current report filed with the SEC.
- Four newsroom items state a publication time and one states a date only.
- Every time is Eastern Time, as the newsroom states it and as you log it.
- You pull the feed under test once an hour and log the time each item first appears in your copy.
- The current report began transmission at 18:05 on Wednesday 4 March and, like most submissions begun after 5:30 pm, received a filing date of 6:00 on Thursday 5 March.
| Item | Start of the clock | First in your copy | Delay |
|---|---|---|---|
| 1. Product launch, newsroom | Mon 2 Mar, 08:00 | Mon 2 Mar, 10:00 | 2 h |
| 2. Partnership, newsroom | Tue 3 Mar, 16:30 | Wed 4 Mar, 09:00 | 16.5 h |
| 3. Leadership change, current report | Thu 5 Mar, 06:00 (filing date) | Thu 5 Mar, 07:00 | 1 h |
| 4. Expansion, newsroom | Thu 5 Mar, 11:00 | Thu 5 Mar, 12:00 | 1 h |
| 5. Award, newsroom, date only | Fri 6 Mar | Fri 6 Mar, 14:00 | Same day |
| 6. Funding round, newsroom | Fri 6 Mar, 15:00 | Mon 9 Mar, 10:00 | 66 h |
- Subtract. Item 2 runs 7.5 hours to midnight and 9 hours into Wednesday, 16.5 hours in all. Item 6 runs 9 hours to midnight on Friday, 47 hours over a weekend in which clocks go forward an hour on Sunday 8 March, and 10 hours into Monday, 66 hours in all.
- Start a filing's clock at its filing date. Measured from the start of transmission at 18:05 on Wednesday, item 3 would show 12 hours 55 minutes. Of that, 11 hours 55 minutes run from 18:05 to 06:00 under the filing rule, before the filing was disseminated, and 1 hour is the feed's.
- Set the date-only item apart. Item 5 is measured to the day, the same day, and is counted apart from the hourly figures.
- Summarise the five hourly delays. In order they are 1, 1, 2, 16.5 and 66 hours. The median is 2 hours, the mean is 86.5 / 5 = 17.3 hours, the slowest is 66 hours, and 4 of the 5 arrived within 24 hours. One weekend item pulls the mean far above the median, so report the median and the slowest together.
- Allow for the pull. Each arrival is known to within the hourly pull, so each delay may be up to 1 hour shorter than logged: items 3 and 4 lie between 0 and 1 hour.
On a sample of your own, run the same steps over the companies you track for several weeks, read the slowest tenth of items rather than the median alone, and count the announcements on the companies' own pages that never reached your copy. For using the dated record afterwards, see event-driven research with Form 8-K filings.
Evidence to verify a company event
Three pieces of evidence verify a company event: the company's own page at its original address, the company's own words on that page, and, for a regulatory filing, its accession number. Together they show what was said, by whom and when, so the event can be checked at its source rather than through a summary.
Check one event in six steps.
- Open the original address. It should sit on the company's own website or on sec.gov; a page elsewhere reports the event.
- Read the date and time on the page with its time zone, and compare them with the record's. If the page has none, the record's date is a first-seen date.
- Read the company's own words against the event type: a customer win filed as a partnership shows in the text.
- For a filing, open its index page for the filing date, accepted time, period of report and items, and compare the period of report with the date of report on the cover.
- Keep the accession number as the key. It identifies one accepted submission; in EDGAR's own example the full text of a filing sits at an address built from the company's CIK and the accession number.
- Check again later. EDGAR's guide says SEC staff sometimes authorise the removal or correction of a filing at the filer's request, and the full and quarterly indexes are rebuilt weekly to take such corrections in.
What documentation is needed to verify a corporate event announcement?
To verify a corporate event announcement you need the original document at its address on the company's own site or on EDGAR, the date and time it states, the company's own text, and for a filing its accession number, filing date, accepted time and items. Keep it with the record so anyone can repeat the check.
Our announcement records carry the address, the date, an excerpt of the company's own text and, for a filing, the accession number and items. The sourcing statement describes where each part comes from, and the entry on data provenance why the trail matters.
Frequently asked questions
What is the difference between the filing date and the accepted time of an SEC filing?
The accepted time is when EDGAR accepted the submission, shown to the second on the filing's index page. The filing date is the business day the filing counts as made. A submission begun at or before 5:30 pm Eastern Time on a day EDGAR operates receives that day's filing date; most begun later receive 6:00 am Eastern Time on the next business day and are not disseminated before that day.
How long does a company have to file a Form 8-K after an event?
The SEC's guidance for companies says current reports on Form 8-K report specified events, often within four business days after the event occurs. The staff's interpretations show the count for one item, the results of a shareholder vote: day one is the day after the meeting ends, so a meeting that ends on a Tuesday gives a period that ends on the Monday.
Why does a news feed show a different date from the press release?
Look for three causes. The feed may date the item by when it first saw it, because the page gave no date. It may carry the time the entry was last updated, which in an Atom feed can change when the publisher edits the entry. Or it may convert a time zone, which can move a late evening release to the next day.
What date does Fokals put on a company announcement?
Company News dates each announcement by when the company published it, as the source states. Where the source gives no date, the record carries the time we first saw it. Each record also carries the title as published, an excerpt of the company's own text, the address of the original and, for a regulatory disclosure, its accession number and the items it was filed under.
Should a back-test use the event date or the announcement date?
The announcement date, or later. A back-test may act on what was public at the time, so use the publication time of an announcement or, for a filing, the later of its accepted time and filing date and, when the strategy runs on a vendor's feed, the time each item reached your copy. The event date belongs to research on the event; timing a trade on it is look-ahead bias.
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