Well, the card is activated when created or when the flow is enabled.
So you could disable the flow and enable it at 20u.
However, when this flowcard is enabled, it will check if the value is meeting the condition. If so, it will use the lastchanged value to start the timer.
So if at 19u59 the value changes and it meets the condition, and you enable the flow at 20u, it will countdown 120seconds from 19u59.
