Sometimes you measure time consumed by a pattern from its highest to lowest point. At other times, you measure from the beginning or end of a pattern. Why?
The first and best method for measuring time in a pattern is to start at the highest and/or lowest points of the wave segment(s) in question and use that information to project or confirm a future turn. If that measurement proves unreliable, the next-best choice is to measure the time of a pattern from its lowest point – in an uptrend or its highest point in a downtrend – to the actual conclusion of the pattern (even if that conclusion is below a high or above a low). Use that measurement to project or confirm a future turn; if that projection also proves unreliable, your assumption about the pattern forming is probably wrong.