Maintenance personnel reported request for structural repair time extension was done in error; resulting in an overfly event.

Narrative

Aircraft X on Day 1 was requested by planning to have Deferred Maintenance Instruction (DMI) XXX/1 (LH wheel well frame XX METAL crack issued on Day 0) extended as it was low on time and is an extensive repair. The pictures planning provided were for the composite webbing on FRAME XX (which was also on DMI YYY/1 separately). I applied to Return to Service (RTS) for an extension of the COMPOSITE WEBBING ON FRAME XX that was on DMI YYY/1 (DMI issued Day 1) based on the pictures; not the METAL FRAME XX CRACK that was what they wanted extended; and got the relief back. The METAL FRAME XX CRACK DMI XXX/1 was extended on accident in the Maintenance Software (unsure of who actually extended it in the maintenance software) and the correct follow up DMI ZZZ/1 for composite webbing crack was issued in ZZZ1 on Day 1. This was brought to my attention on Day 2 and after some investigation I realized I applied for the wrong damage to be extended per planning's request. The DMI that ended up getting extended was for the METAL FRAME XX CRACK and resulted in overflying it.Suggestions: I should have looked closely at the DMI number as well as the provided pictures and caught the discrepancy between the 2.