This table summarizes the dates that already existing Atom/RSS weblog publishing systems are capable of providing.
Below, Change Date refers to a system maintained modification time, no "significance of change" or "visible change in output" is intended or implied. If any of the tools listed have been misappropriately listed as a "no significance of modification" when they actually have some way to indicate significant change, please note or correct the table.
|Tool||Display Date||Change Date||Creation Date|
|WordPress||n/a||<?php the_date('Y/m/d','before','after',display); ?> or a plugin||n/a|
|JournURL||<weblog:date type="published">||<weblog:date type="updated">||<weblog:date type="created">|
|Macsanomat||publication date, modification date also if different||modified date||n/a, publication date closest|
|Blosxom Atom plugin||n/a||$atomfeed::utc_date||n/a|
This section contains detailed description about each date in a given publishing system. It should be described what the date is used as in the publishing tool, if and when it's changed, when it's provided, and whether it is objective or subjective.
The time a User wishes their Post to first appear. Posts dated in the future do not appear until that date. Editable by the User.
The last time this post was modified. Not editable by the User.
When this post was created. Not editable by the User.
This date is first provided when the entry is saved. After that, it may be altered by the user. This date is used for sorting entries on the front page of the blog, and in the RSS and Atom feeds. This date is also used in the atom:created and atom:issued elements in most of the existing Movable Type Atom templates. In the default RSS 1.0 and 2.0 templates, this date is used in the dc:date element.
This date is set and updated every time a user presses [Save] in Movable Type. This date is used in the atom:modified element in most of the existing Movable Type Atom templates.
- <weblog:date type="published">
This date can be defined or altered by the user during the creation or editing of an entry, and is intended to be the author's "official" date associated with an entry. If the field is left blank during creation, it defaults to the creation date. (See below.) The date is used to sort entries in various templates, including HTML and RSS. This is also the date that would be most likely used in permalinks. In Atom 0.3, its closest equivalent is atom:issued. As with all these date tags, an optional type attribute allows it to produce RFC822- and W3CDTF-style dates, as well as human-readable values. Another characteristic these dates share is that they are all converted to UTC before being stored in the database.
- <weblog:date type="updated">
This date is machine-generated. Upon creation of any entry, it is set to match the creation date. (See below.) Upon each successive edit, the date is changed to the time of that edit. "Edit" in this context means virtually any change in the status or content of the entry, from significant alterations of text to something as small as toggling one of the entry's attributes. This date is used as the defaukt sort order for entries within the forum interface shared by all blogs within a community.
- <weblog:date type="created">
This date is machine-generated, and never changes after the moment of creation. However, due to JournURL's nature, the date doesn't mean anything in the context of an individual blog. It is meant to be primarily used within the community interface, where it is used to fill the dc:date/pubDate elements in RSS feeds.
Blosxom Atom plugin
This date is derived from the filesystem modification datetime of the Blosxom story file. It is output in Atom 0.3 in the <atom:issued> and <atom:modified> date fields. Other modules can extend or change this functionallity:
entries_index can preserve the initial creation time of the story, but the atomfeed module does not support that module.
entries_index_tagged forces story dates to a value found within the files themselves
metadate allow you to put metadates into an external file
update allows past posts to be updated
News reading tools
The following summarizes the dates that are used in existing Atom/RSS reading tools.
AmphetaDesk: Doesn't use item level dates. Lists all entries from feeds in feed order (ie. has no concept of "marking as read" or new items). Sorts feeds by the local system most-recently fetched time.
Feedparser: Maps all RSS dates to "last modified" in Atom 0.3 terms.
FeedReader: Stores only one date field. Sorts based on that date field. In RSS1/2, prefers dc:date over pubDate. In Atom 0.3, prefers atom:created over atom:issued. atom:modified is not used.
NetNewsWire: Will sort on RSS pubDate
NewsGator: Uses the entry's <atom:modified> timestamp as both Sent: (displayed as Posted: on the entry note) and Received: (presented in the index and typically used for sorting), with the date-time of download from the site feed recorded in the Modified: property (not displayed on the entry note). All displayed times are restated as local time.
Opera: Prefers dc:date over pubDate. Uses dc:date/pubDate for display. If a date is missing from an entry, the feed-level dc:date/pubDate is used, and if that is missing as well it will use "Received" time for display. When Opera is set to sort entries by this date, it will sort by this date. Opera versions 7.51 and later do not appear to update changed entries.
Peerkat: Not applicable. Peerkat seems only to read RSS 1.0, and it may pass on dc:date to downstream feeds. However, the only date displayed, and sorted on, in its feed/item distribution selection is the date the item was received and stored locally in its database.
RSS Bandit: Stores dc:date/pubDate first time it is received and never overwrites it when the entry changes. Uses dc:date/pubDate for item display and sorting. Does not indicate changed items in any way.
Straw: Uses Feedparser (2.7.5). Displays and sorts on Feedparser's item.date_parsed (dc:date, pubDate, atom:modified).