# iCal (.ics) file format question: DTSTAMP vs CREATED **URL:** \ **Category:** Factual Questions\ **Created:** [May 28, 2010, 7:09pm UTC](https://boards.straightdope.com/t/ical-ics-file-format-question-dtstamp-vs-created/541104 "2010-05-28T19:09:30Z")\ **Posts on this page:** 8\ **Page:** 1
**Author:** ![toadspittle](https://avatars.discourse-cdn.com/v4/letter/t/c0e974/32.png) [@toadspittle](https://boards.straightdope.com/u/toadspittle)\ **Post date:** [May 28, 2010, 7:09pm UTC](https://boards.straightdope.com/t/ical-ics-file-format-question-dtstamp-vs-created/541104/1 "2010-05-28T19:09:30Z")
I’m trying to set up my CMS to create .ics files of our org.'s future events. One question: What’s the purpose of DTSTAMP, and how does it differ from CREATED? Here’s the documentation: [http://www.ietf.org/rfc/rfc2445.txt](http://www.ietf.org/rfc/rfc2445.txt) > [@](#): > > **4.8.7.1 Date/Time Created** > > Property Name: CREATED > > Purpose: This property specifies the date and time that the calendar > information was created by the calendar user agent in the calendar > store. > > ``` > Note: This is analogous to the creation date and time for a file > in the file system. > > ``` > > Value Type: DATE-TIME > > Property Parameters: Non-standard property parameters can be > specified on this property. > > Conformance: The property can be specified once in “VEVENT”, “VTODO” > or “VJOURNAL” calendar components. > > Description: The date and time is a UTC value. > > Format Definition: The property is defined by the following notation: > > ``` > created = "CREATED" creaparam ":" date-time CRLF > > creaparam = *(";" xparam) > > ``` > > Example: The following is an example of this property: > > ``` > CREATED:19960329T133000Z > > ``` > > **4.8.7.2 Date/Time Stamp** > > Property Name: DTSTAMP > > Purpose: The property indicates the date/time that the instance of > the iCalendar object was created. > > Value Type: DATE-TIME > > Property Parameters: Non-standard property parameters can be > specified on this property. > > Conformance: This property MUST be included in the “VEVENT”, “VTODO”, > “VJOURNAL” or “VFREEBUSY” calendar components. > > Description: The value MUST be specified in the UTC time format. > > This property is also useful to protocols such as [IMIP] that have > inherent latency issues with the delivery of content. This property > will assist in the proper sequencing of messages containing iCalendar > objects. > > \*\* This property is different than the “CREATED” and “LAST-MODIFIED” > properties. These two properties are used to specify when the > particular calendar data in the calendar store was created and last > modified. This is different than when the iCalendar object > representation of the calendar service information was created or > last modified.\*\* > > Format Definition: The property is defined by the following notation: > > ``` > dtstamp = "DTSTAMP" stmparam ":" date-time CRLF > > stmparam = *(";" xparam) > > ``` > > Example: > > ``` > DTSTAMP:19971210T080000Z > > ``` What the heck is a calendar store? Are these engineers saying that DTSTAMP is a property employed by the event hosts, and CREATED is a property employed by the end-user (i.e., to specify when the app on her local machine first stored the event information on her hard drive)? ---
**Author:** ![Left\_Hand\_of\_Dorkness](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/left_hand_of_dorkness/32/7156_2.png) [@Left\_Hand\_of\_Dorkness](https://boards.straightdope.com/u/Left_Hand_of_Dorkness)\ **Post date:** [September 12, 2012, 8:02pm UTC](https://boards.straightdope.com/t/ical-ics-file-format-question-dtstamp-vs-created/541104/2 "2012-09-12T20:02:26Z")
> [@toadspittle](#): > > What the heck is a calendar store? [Not sure why this is a difficult question, but here you go](https://www.google.com/search?q=calendar+store&sugexp=chrome,mod=18&sourceid=chrome&ie=UTF-8). ---
**Author:** ![Drunky\_Smurf](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/drunky_smurf/32/449_2.png) [@Drunky\_Smurf](https://boards.straightdope.com/u/Drunky_Smurf)\ **Post date:** [September 12, 2012, 8:12pm UTC](https://boards.straightdope.com/t/ical-ics-file-format-question-dtstamp-vs-created/541104/3 "2012-09-12T20:12:36Z")
I’m sure your assistance is going to help him out in his problem. [spolier]This thread is over two years old.[/spoiler] ---
**Author:** ![Shagnasty](https://avatars.discourse-cdn.com/v4/letter/s/9dc877/32.png) [@Shagnasty](https://boards.straightdope.com/u/Shagnasty)\ **Post date:** [September 12, 2012, 8:17pm UTC](https://boards.straightdope.com/t/ical-ics-file-format-question-dtstamp-vs-created/541104/4 "2012-09-12T20:17:45Z")
> [@Drunky\_Smurf](#): > > [spolier]This thread is over two years old.[/spoiler] How can you tell? ---
**Author:** ![PacifistPorcupine](https://avatars.discourse-cdn.com/v4/letter/p/7ea924/32.png) [@PacifistPorcupine](https://boards.straightdope.com/u/PacifistPorcupine)\ **Post date:** [September 12, 2012, 8:18pm UTC](https://boards.straightdope.com/t/ical-ics-file-format-question-dtstamp-vs-created/541104/5 "2012-09-12T20:18:09Z")
Especially since “calendar store” is used in a very specific context here and a google search for calendar store is not helpful. For anyone curious, a calendar store is (from [here](http://www.ietf.org/rfc/rfc3283.txt)): ``` A data store of a calendar service. A calendar service may have several calendar stores, and each store may contain several calendars, as well as properties and components outside of those calendars. ``` ---
**Author:** ![Drunky\_Smurf](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/drunky_smurf/32/449_2.png) [@Drunky\_Smurf](https://boards.straightdope.com/u/Drunky_Smurf)\ **Post date:** [September 12, 2012, 8:18pm UTC](https://boards.straightdope.com/t/ical-ics-file-format-question-dtstamp-vs-created/541104/6 "2012-09-12T20:18:51Z")
That is one of my many superpowers. @ Shagnasty. ---
**Author:** ![Left\_Hand\_of\_Dorkness](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/left_hand_of_dorkness/32/7156_2.png) [@Left\_Hand\_of\_Dorkness](https://boards.straightdope.com/u/Left_Hand_of_Dorkness)\ **Post date:** [September 12, 2012, 8:28pm UTC](https://boards.straightdope.com/t/ical-ics-file-format-question-dtstamp-vs-created/541104/7 "2012-09-12T20:28:53Z")
> [@Drunky\_Smurf](#): > > I’m sure your assistance is going to help him out in his problem. > > [spolier]This thread is over two years old.[/spoiler] Ohhhhhhhhhh. > [@PacifistPorcupine](#): > > Especially since “calendar store” is used in a very specific context here and a google search for calendar store is not helpful. Ohhhhhhhhhh. > [@Shagnasty](#): > > How can you tell? Probably has something to do with the calendar store. ---
**Author:** ![CarnalK](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/carnalk/32/486_2.png) [@CarnalK](https://boards.straightdope.com/u/CarnalK)\ **Post date:** [September 15, 2012, 5:01am UTC](https://boards.straightdope.com/t/ical-ics-file-format-question-dtstamp-vs-created/541104/8 "2012-09-15T05:01:13Z")
Here you go: > **[iCalendar](https://en.wikipedia.org/wiki/ICalendar)** > > The Internet Calendaring and Scheduling Core Object Specification (iCalendar) is a media type which allows users to store and exchange calendaring and scheduling information such as events, to-dos, journal entries, and free/busy information, and together with its associated standards has been a cornerstone of the standardization and interoperability of digital calendars across different vendors. Files formatted according to the specification usually have an extension of .ics. With supporting s iC... FTW.