Mindfulness is not something you do for an hour a day it’s something thing you do to reinforce the mindful state for an hour a day.
Then during the day you are able to watch your mind and all the decisions you make. We often make decisions mindlessly and based on the the way we have been indoctrinated by others, mindfulness allows us to review our choices and decide from a far more insightful point of view.
Mindfulness showed me how to decide based on compassion, when anger arose instead of wanting to hurt or punish someone I could make a more compassionate and insightful decision.
I became vegetarian because when deciding what to eat I could make the more compassionate choice not to kill or harm animals.
I learned how to become more compassionate toward myself as the person we tend to hurt and be angry with is ourselves.
So mindfulness is a 24/7 job and can reinforced with seated practice giving us insight during meditation practice.