If you plan on doing timing work on an intraday chart, if at all possible,
choose a time frame chart that will divide equally or pretty close to
equally into the trading session. For examples, there are 405 minutes in the
day session in the indexes, from 8:30 a.m. central time to 3:15 p.m. central
time. As long as I am analyzing only day-session data, I can divide that
405 minutes into 3 bars with a 135-minute chart, or I can divide it into
9 bars with a 45-minute chart, or into 27 bars with a 15-minute chart. These
time charts all divide perfectly into the 405-minute session. If the time
period you use doesn’t divide well into the session hours, the timing
results on your intraday work could be compromised by a discrepancy in
the last bar of the day.