Geologic time is a fundamental concept in the geosciences, but research shows that a gap exists between what students are taught about geologic time and the actual time scale of the Earth. The literature further indicates that instructors are not given adequate tools to teach geologic time as part of their training. One set of traditional teaching methods has focused on the use of metaphors to explain the timescale, entailing techniques such as to counting off the geologic eons, eras and periods on the face of a classic 24-hour clock. Laying out the timescale proportionally on a sidewalk or an outside area is another illustration. A different instructional approach involves rote learning and memorization of critical events. These ways of teaching, through metaphors and memorization, pose challenges for understanding because students may not grasp them readily or find them relevant to their lives. Further barriers to student learning include the great length of geologic time relative to the human lifespan, the use of exponential numbers and ratios for the timescale, and religious and social preconceptions. What is the current understanding in the literature about teaching geologic time? A meta-analysis of techniques, presently employed, is explored. Then the question is asked, are there other ways to teach geologic time? Having a grasp of the timescale of geology is vital in understanding the human role on the planet in light of critical climate change and environmental challenges. The timescale of the Earth provides both a context to situate all life and an understanding of how the Earth works through its processes, including climatic events from the geological past.