“T.E.C. data for hard disk”是什么

＂Drive Health＂２.0BETA5版说:The nearest predicted T.E.C date for Hard Disk WDC WD*)JB-***...212 is closer than 3 days! We recommend you to start backup of all critical data from this disk.

请问“T.E.C. data for hard disk”是什么？