Citizen Japan launched a new calibre with three new “Geo Trekker” models in the Promaster Sky range. The BY3005-56G has a black case, bracelet and dial, the BY3006-53E has a black dial with green details, and the BY3006-53H has a gray dial and monochrome color scheme. All models have 46mm diameter stainless steel cases that are 11.5mm thick. They utilize the new H.864 calibre, named after the 86,400 seconds in a day. It has a sub-dial at 6 o’clock with a map of the northern hemisphere that rotates once a day. The calibre has a radio wave reception function (Japan, China, America, Europe), 26 zone world time function, perpetual calendar, and a 2.5 year power save function when activated. The city notation on the dial and the numbers on the disc use a different font, with the aim to improve legibility differentiating it from that of the aviation slide rule section. The case back is engraved with a map of the northern hemisphere.