What does のですが mean in the following sentence?

Question

焼き鳥屋さんで集まったのですが、とても楽しい、かつ有意義な時間を過ごしました。

Answer 1

～のですが (or ～のですけれども, or ～んだけど, or any of a number of variants) is often used in this way to "set the stage" and provide a context for a succeeding clause or sentence. Here, the purpose of ～のですが is to mark information that will help the listener understand the second half of the sentence. As such, the が here is best translated into English as "and", not "but".

This is one of the many uses of ～のだ to provide supporting information for other statements.