For Alkylate 2-stroke oils (example: Husqvarna XP POWER) in its original can the storage time is 3 years if opened and 5 Yrs if not opened.
For gasoline ( SP 98 / SP 95/ SP 95 E 10) and ready fuel mixture, the storage time is 1 month maximum.
Please also in addition pay attention to always use the correct type of can or barrel for storing the fuel and fuel mixture.
Prior to refueling the trimmer/brush cutter please make sure to mix the mixture properly, to avoid separation by settling.