There are several definitions of what is considered "shincha". The widest definition refers to any leaf in the first two months or so after harvest (when the leaves are still "new"). General use of the term refers more specifically to the spring harvest, and the first two months or so afterwards. This means the same spring tea called shincha in May is no longer called shincha in August because it is no longer new.
However, many farmers will harvest extra early for particularly young, tender leaves. These have several names: hashiri - "run", as "in run to the fields now to harvest the leaves", hatsutsumi - "first picking" or the farmer's very first harvest of the spring season, hachijyu hachiya - "88th night" referring to the 88th day of spring in the old lunar calendar, tea picked on this day is said to be the best and brings good fortune for the year (this year it is May 2nd).
The period during which shincha is available is short for most vendors, but since we are aggregating producers from throughout Japan, the harvest of tea leaves occur from the beginning of April all the way until July.
This year, we will be adding teas to this section as they become available for shipment, while pre-orders will be handled with "surprise me" products.