Harvest Date Calculator
Estimate harvest dates from planting, or work backwards from a desired harvest. Distinguish maturity measured from sowing versus outdoor transplanting.
Starts with an editable example. Replace the dates and rules with your own.
Your calculation
Ready when you are
Choose your dates.
Select your counting rules and calculate.
Calculation details
| Step | Value |
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How to use this calculator
Choose the planning direction and anchor date, enter the maturity range and its starting basis, and optionally enter indoor days before transplanting and the season's final harvest date.
The anchor is day zero. Forward planning adds the maturity range; reverse planning subtracts the longest duration first. Indoor sowing is estimated only when maturity starts at transplanting. User-entered maturity ranges are not crop guarantees.
A worked example
Sowing May 2, 2027 with 60–90 days to maturity estimates July 1–31. For a desired July 31 harvest, the corresponding planting window is May 2–June 1.
Which maturity basis should I choose?
Use the basis specified by your seed packet, plant supplier or growing records. Days from sowing and days from transplanting are different inputs and should not be mixed.
Which calendar and years are supported?
Use Gregorian dates from 1900 through 2100, with results in that range. Daily attendance, office, coverage and chore plans allow up to 366 dates; school cycles, course plans and milestones allow up to 731. Dependency and historical workday calculations scan at most 3,661 dates. Class-session searches allow 366 dates and 200 sessions. Time-zone tools use browser IANA rules and require a choice when local times repeat. Dates and policy rules are entered manually; no employer, retailer, school or local weather policy is inferred. Copy, CSV and printing include the calculation rules; calendar exports appear when the result contains dated events.
What happens to my dates?
Calculations run on your device. Saving a calculation is optional and keeps it in this browser. A setup link contains the dates and settings you entered; anyone with the link can read them. Use one tab per saved calculator. Clear saved data from Privacy & settings.