In the family Fagaceae, fertilization is delayed by several weeks to more than one year after pollination, leading to one- or two-year fruiting species depending on whether fruiting occurs in the same or the next year of flowering. Although delayed fertilization was recorded over a century ago, underlying mechanisms remain to be explored. To uncover the key genes associated with delayed fertilization, we obtain and analyze the comparative molecular phenology data over two years in one-year (Quercus glauca) and two-year fruiting species (Lithocarpus edulis). Overall design: Lead and bud samples were collected from May 2017 to February 2019 from Quercus glauca (Qg). Samples were collected from three individuals. Sample title indicates "year_month and day_individual ID".