The Vultro Calendar is a calendar system established solely in the Vultroverse, meant to prevent ambiguity due to the various calendar systems used across Sonic media. Based on the real-world Gregorian calendar, it asserts that 0 BBV is the year of the birth of Vultro the Fox. Any events that occurred between January 1st and July 26th of that year are still considered 0 BBV despite being before Vultro's birth. For instance, someone born 2 years after Vultro would have a birthdate of 2 ABV, regardless of if their birthday is January 1st or December 31st.
In relation to other major events in the Sonic series, the events of Sonic the Hedgehog take place in 8 ABV. This anchor point is used to estimate character ages in relation to other major canon events.
The Vultro calendar also makes a clear assertion about when 0 ABV takes place in relation to other common calendars: 3219 on the Mobius (Archie) calendar, and 13999 CE on the Gregorian calendar. Its relation to the calendar of the post-Genesis Wave continuity is unclear due to it not having a clearly established calendar.
The current year according to the Vultro Calendar is 29 ABV.