We have released an update to the way in which we render dates in the UI across the network.
Up until now, whenever a date that included the year was rendered (which would typically be for dates earlier than the current calendar year), we would only show the last two digits of the year (for example: Jul 15 '09).
While the apostrophe-two-digit year format was originally put into place for the sake of brevity, we have found out through user research that this two-digit date format can be confusing to some users, especially to those who have learned English as a second language.
The change presented here is being put into place to address this, with the hope of making dates clearer to all users, without sacrificing significant space in the process (trading one apostrophe for two digits). So the date above is now presented as Jul 15 2009.
Nothing else has changed as part of this, including showing all dates in UTC, the format of date tooltips, or the way that we abbreviate months. Also, the date format has not been changed at all on the international sites.
We're happy to receive your feedback or address any questions/concerns about this change.