Time of Day is very important!
For instance:
What I've noticed over the last 10 years.
10am et. many economic numbers are released at this time that has major impact on the market.
10:20-10:30am et. usually a major program trade kicks in.
11:15-11:30am et. European markets are getting ready to close.
12:00-1:00pm et. Wall St. Lunch hour, if markets are moving, they will stall at this hour!
1:30pm et. usually the market will start moving at this time with big program trades.
2:15-2:30pm et. usually more activity is done in this time period, why? I really dont know why? it just happens with great frequency!
3:00- 3:10pm et. Bond futures close, last hour of trading starts.
3:40pm et closing order trade imbalances announced.
3:50pm et End of day buy/sell programs kick in for close.
Well these are just some of the "time of day" happenings I've seen and experienced over the years.
Good Luck!