Counting days away from an ex just reinforces loss and subtly keeps you focused on the past and what you don't have anymore. It keeps you stuck in the past and thinking about your ex.
Counting days of dedicated self improvement, investing in ACTIVITIES that better yourself now, for an even better future, (that may include refraining from contact with an ex), is a whole different focus. When done properly, it can result in a better you and a better life, than you ever knew before. Counting in this way can create a focus on momentum, which can be powerful.
Making choices that truly move you on and make you a better man, after a break-up, is what matters most, not how you get there. Just get results.