Valid in 6 months counting from the purchasing date.

自购买之日起6个月内有效。

youdao

The supply department shall be responsible for tracing to the purchasing date and supplier during In-coming inspection.

进货检验中由供应部负责追溯到进货日期与供方。

youdao

When purchasing perishable food items I look for those that have the longest "use by" date, even if I intend to consume them immediately.

在采购易腐食品时，我会寻找那些距离保质到期时间最远的商品，尽管我往往也会立即把它们吃掉。

youdao

To that end, the program would ask passengers to supply their name, address, phone number and date of birth upon purchasing a plane ticket.

CENTERFORSECURITYPOLICY: Balancing security and privacy during wartime

Entirely possible that second and fourth quarters will be booming, while first and third relatively poor as people hold off on purchasing the soon to be out of date of either the iPad or iPhone line.

FORBES: Apple's iPad 3 Out in Spring: Maybe