Time isn't taken into consideration because we don't identify ourselves that way much. It matters in Astrology because the closer planets - and earth - move so fast.
With numerology we're studying the numbers and letters we surround ourselves with, that make up our identity. It's possible that if we included our time of birth more that numerologists would pay more attention to those numbers! :)
Ellin Dodge said in a seminar that I attended that she helps forensic investigators wtih timing using numerology. She was actually consulted on the Janis Joplin case because they needed to know her time of death, and I do believe she worked out all the minutes and even seconds numerology wise. The doctors were confused because she shot up and then bought cigarettes before she OD'd.