The micro SD card that comes in the package is 16GB. ATLI EON supports up to a maximum 128GB micro SD card. Memory usage depends on the time lapse output setting. You can either select Video only or Video + Photo Sequence.
Photo Sequence takes up more memory since all frames taken will be stored separately in jpg format. For long duration time lapse shooting, it would be important for you to estimate how much memory is required and decide whether a larger capacity SD card is required or adjusting the shooting interval to accommodate the capacity of the SD card.