In their marine habitat, marine mammals are faced with numerous challenges that could be mastered with a sense of time. In this dissertation the temporal abilities of two pinniped species, the harbor seal and the South African fur seal were examined and fundamentally characterized. Both species found access to temporal information with ease, were able to discriminate temporal intervals with high precision, and could even learn complex temporal tasks. The pinniped sense of time is thus well-developed and could provide seals with information in the contexts of foraging or orientation/navigation.<eng>