Citizen Tsuyosa Collection (Refs: ), Citizen JDM “NK” Collection (Refs: NK0000-95E, etc) (Add your watch in the comments below…)
The Citizen caliber 8310 is a self-winding automatic movement with 21 jewels. Several time+date 3-hand dress watches with this movement were introduced in September 2019. This caliber is made in Japan.
Citizen 8310 VS Miyota 8310:
Although this caliber is exclusive to Citizen, it is made by Miyota, which is part of Citizen Watch. With there also being a similar Miyota caliber 8315, there is often caliber confusion with some members of the community looking for information regarding “Miyota 8310”. Please note: technically this is the Citizen caliber 8310 and not Miyota 8310 (even if it produced by Miyota).
Citizen 8310 VS 8210:
There is a similar Citizen caliber 8210, and auto with 3 hands and a date at 3:00. The 8310 appears to be an evolution of that movement, with the main difference being that the 8210 offers a power reserve of at least 40 hours and the 8310 has a runtime of 60+ hours. At the time of this caliber listing, Citizen’s official site (at least the site shown to North American and English speaking customers) does not return any search results for “8310”. In fact, searching for 8310 simply displays 5 “Tsuyosa” Collection timepieces, all powered by the 8210 (see below).
The accuracy of the Miyota version of the 8310 (Miyota 8315 as mentioned above) is -20~+40 seconds per day. The Citizen 8310 can be expected be within that range or better.