For me, the difference between speculating and investing is affected by liquidty risk.

Focussing on the time frame or the intention takes attention away from a crucial and often forgotten part of the process: The need for someone to take you out of your transaction.

I think that if your plan involves eventually selling your asset to someone else, whether that is in 8 seconds or 30 years, then you are speculating, not investing.

If you need someone to “take you out” of a position in order to make a return, then you are exposed to liquidity risk i.e. the risk that the market may not be able to buy at the time you wish to sell, and vice versa.

This definition puts most stock market "investing" in the speculation category, since most people plan to exit their position by finding another monkey willing to buy it.