Asalamualykum
Sometimes I'm at work so I can't get to the mosque at the designated time. Can I still go and pray outside of these times?
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Sign up to join this communityAs mentioned by Yahia, you can pray the missed salah in mosque within the boundaries of the beginning and end times. Praying outside this time would be classed as qaza which can obviously also be prayed in a mosque.
If there are a few of you at work or you find other brothers in the mosque who have also missed the jamaah time of that particular salah at that mosque then it would be better that you did your own jamaah of that particular salah, rather than praying individually.