The advise "Don't time the market" alludes to not operate on it merely because you think something is going to go up or down in short-term.
Let's suppose a small investor has a savings plan by which he invests a fixed amount each month. If that investor decides to stop buying a fund/stock/bond (not selling it, just not buying) because its PE ratio is "very high" (say, historical maximums), even if that means not buying it for a long time, is that "timing the market"?