The time factor operates similarly to geolocation. The author sets a range by spinning the dial from 1 minute to 30 days, and then slides the tab to say "only within this time range" or "only outside of this time range.".
The range timer starts at the moment you create the share, not necessarily when you share it later. Then, access is restricted by the timer from that moment, determining valid or invalid access. The timer cannot be reset, only disabled, and re-enabled. Tapping opens the factor up to edit and long-pressing the icon resets/clears the factor for that share.