To make a prediction about the moon phase on December 15, 2024, I would need to see the specific graph you're referring to. However, based on the typical lunar cycle, it lasts about 29.5 days, and the phases progress in a regular sequence through new moon, first quarter, full moon, and last quarter.
If you know the moon phase on a certain date in December 2024, you can approximate the moon phase on December 15 by counting the days from that known phase. Alternatively, you could consult a lunar calendar for 2024, which would provide you with the exact moon phase for that date.
If you provide the current phase or context, I can assist in narrowing down the options!