Standard Wildspace Reckoning, abbreviated SWR, refers to the official Tinris calendar system as of 1/0/Concord. This calendar system replaces Old Tinris Reckoning in all official capacities.
Standard Wildspace Reckoning came about in the wave of cross-continuum cooperation following the Tinris World Navy's joining with the Persean Concord Navy in the newly formed Naval Joint Command. It is considered one of the foundational measures of cooperation, as it represents such a dramatically different system from the previous Tinris calendar - now considered Old Tinris Reckoning, as outlined by Harhpatoca the Tenfold - which had been in continuous use since pre-Collapse history. Nonetheless, the basics of timekeeping required to manage a simultaneous operation on the scale of the Naval Joint Command's mission exceeded that which could easily be maintained.
So it was that on Calibration, 1/0/Concord that a joint conference of high ranking officials within the Tinris World Navy, Persean Concord Navy, Church of the Stars and members of various faiths of Tinris - primarily represented by the faithful of Nicholas Greenfoot - convened to enact the Law of Standard Wildspace Reckoning.
As much of the calendar is derived from the dominant Oloun Calendar in use throughout Concord Space, the format is similar. In the interests of simplicity, however, it was decided that Standard Wildspace Reckoning would use a set of 13 months of 28 days each.