Is "since" ambiguous?
Cambridge Dictionary - Since: from a particular time in the past until a later time, or until now
However, whenever I hear: "I haven't done x since y." I interpret it as the last time they did "x" was "y".
However, by the dictionary, it means 'from y on, I haven't done x." (The last time I did "x" was before "y".
Is there a reason why?
What if you say: "I haven't done x since y on." Does this make sense.