What is the deadline for filing an opposition?

In Russia: An opposition could be submitted to the RUPTO by any party anytime time during patent life, or by an interested party after patent expiry period.

In Eurasia: An opposition could be submitted to the EAPO within 6 months from the date of patent publication in the EAPO Official Bulletin. If the opposition is satisfied, the patent will be invalidated on the territory of all contracting states. Alternatively, a notice of opposition can be filed in one or several contracting states individually according to the procedural rules acting in that state.