We propose a novel model based on a set of coupled delay differential equations 
with fourteen delays in order to accurately estimate the incubation period of 
COVID-19, employing publicly available data of confirmed corona cases. In this 
goal, we separate the total cases into fourteen groups for the corresponding 
fourteen incubation periods. The estimated mean incubation period we obtain is 
6.74 days (95% Confidence Interval(CI): 6.35 to 7.13), and the 90th percentile 
is 11.64 days (95% CI: 11.22 to 12.17), corresponding to a good agreement with 
statistical supported studies. This model provides an almost zero-cost 
computational complexity to estimate the incubation period.