Calculate planting and harvest dates, intervals between farm operations, and growing degree days.
Plan your farm schedule with three calculation modes: start date + days = end date, end date - days = start date, and days between two dates. Perfect for scheduling planting, spraying, irrigation, and harvest. Count backward from your target harvest date to find the optimal planting window.
You planted tomatoes on May 1st expecting harvest by August 1st, but the variety needed 95 days, not 60. First ripe tomatoes appeared August 4th — after your restaurant buyer had already switched to another supplier. A one-week delay cost you a $3,000 contract. Always count backward from the target harvest date.
Choose mode: "Add days to date" or "Days between dates". For add mode: enter start date and number of days to add (or subtract). For difference mode: enter two dates. Click calculate to see the resulting date, day of week, and number of days.
The agricultural date calculator helps you plan planting, spraying, harvesting, and other time-sensitive farm operations. It calculates dates by adding or subtracting days, determines the number of days between two dates, and helps you track crop growth stages, pesticide intervals, and growing degree days.
A: Determine your average last spring frost date (from local agricultural extension or weather records). Count backward from that date by the number of weeks needed for seedling establishment: warm-season crops (corn, beans, tomatoes) plant 0-2 weeks after last frost; cool-season crops (lettuce, peas, broccoli) plant 2-4 weeks before last frost. Use this calculator to find exact planting dates.
A: PHI is the minimum number of days that must pass between the last pesticide application and harvest. It ensures pesticide residues are below safe limits. PHI varies by pesticide and crop: commonly 7-14 days for vegetables, 14-30 days for fruits, 30-60 days for some systemic pesticides. Always check the pesticide label for exact PHI. Use this calculator to determine safe harvest dates.
A: GDD measure heat accumulation for crop development. Formula: GDD = ((Max Temp + Min Temp) ÷ 2) - Base Temperature. Base temp varies by crop: corn 10°C, wheat 0°C, soybeans 10°C, alfalfa 5°C. GDD are accumulated daily and compared to crop requirements (e.g., corn needs ~2700 GDD from planting to maturity). This helps predict harvest dates and assess growing season suitability.