1. Weeks are easily removed form the timer by activating the Omit Weeks checkbox in the widget, or using the omitweeks attribute in the shortcode. Examples of this are demonstrated for your viewing pleasure on the documentation page.
2. Days can be removed, but you will need to know a bit of css to set the
.<your_style_name>-days_dash to display:none; It's not part of the existing plugin, but it can be 'hacked' if you know your way around css.
3. If you want a way to have the timer recur—that is count down, pause (or not) then count down again— this is a feature available only in the pro version: T-Countdown Control. This is exactly what the pro version was built to do.
If you do decide to go with the pro version, we would be happy to build in a special 'omitdays' feature just for you.
Hope this helps point you in the right direction!