A countdown is a common way to align everyone towards some event - the launch of a space mission or start of a new year for instance, or the completion of your GDPR compliance project. As a communications, awareness and motivational technique, countdowns work well for that rather narrow objective, focusing attention on a given point in time.
With a little more creativity and effort, it's not hard to use countdowns to get people to re-assess their progress and maybe prioritize things on the way down to the deadline ... and then to follow-through with count-ups - in other words, keep the timer going past the zero point, displaying the time since the deadline passed or expired.
This is often done for overdue activities, starting with gentle reminders then steadily ramping up the pressure (red reminders, warnings) and perhaps escalating matters (court orders, bailiffs) as time marches inexorably on.
Before you know it, the point-in-time spot focus has turned into a zone of concern, with an accompanying sequence of activities, a plan and a process.
The passage of time can also be used in a more positive manner, in the sense of "Look how far we've come!". It is generally implied in the concept of maturity. It takes time to reach then stabilize and become comfortable at each level before starting the assault on the next, like climbing the stairs or a mountain. [Maturity also implies gaining competence and wisdom, which are the more obvious objectives.]
A related concept is that of momentum or inertia - winding things up to reach a critical speed, then sustaining it as long as possible. This is not just Newton's first law of motion as it literally applies to boulders, wheels and space rockets in the physical world. It's also figurative, applying to organizations and processes, even to individuals. Our energy/activity levels and motivations vary and, to an extent, can be influenced by others. Some things fire us up and get us going. Others wear us out and exhaust us. Understanding the difference goes a long way towards making awareness activities more effective.
I'll end with a simple suggestion to use the countdown to the GDPR go-live deadline quite deliberately as a means to align and drive everyone to May 25th, and perhaps to lead them ever onward and upwards thereafter, having hopefully achieved the specific goal. Privacy is no less important on May 26th!