According https://zindi.africa/competitions/predict-the-global-spread-of-covid-19/discussions/1093:

For the final evaluation you need to provide predictions for 19 April 2020 to 8 June 2020, inclusive. Even if you get the error message, your submission will still be evaluated. To appear on the current public leaderboard, you can include predictions for all the dates starting from 2 April 2020. (Though we recognize and assume that you have access to the most up-to-date public data from JHU, so these predictions will not affect the final score in June.)

Correct it is 51 days, not 49 days.

you need to have the following format : "Afghanistan X 4/2/20" instead of "Afghanistan X 04/02/20" !