A device is disclosed herein, said device for determining whether a day is suitable for planting a seed on a plot of land, said device comprising a microprocessor programmed to: (a) select at least one electronic data source containing meteorological data and/or soil temperature for the plot of land by a method comprising: (a1) determining the location of the plot of land; and (a2) selecting a data source providing local weather forecasting services and/or soil data services for the location of the plot of land; (b) electronically receive from the at least one electronic data source: (b1) meteorological data for the plot of land comprising a high surface air temperature and a low surface air temperature for each of the plurality of consecutive days; and (b2) at least one soil temperature for each of the plurality of consecutive days; and (c) select an alpha day within the plurality of consecutive days and determine whether it is suitable for planting the seed based on the meteorological data, the soil temperature, and a species of seed to be planted.