How long does it take an achilles' tendon tear to heel after surgery to fix it has been done?

This would : Be variable as different patients present with different extents of the injury. Some tendons can be shredded or retracted and they will heal at a different rate then say a clean laceration. Some tears are partial, some complete so all these factors come into play.

Tendon healing: Recovery takes a while (3-4 months), but tendon healing takes roughly 3-4 weeks. Functional rehab (aggressive rom exercises non weight bearing) during the first 2-4 weeks after surgery has shown to improve recovery times for athletes with assisted WB after 4-6 weeks. Hope this helps.