Harvest Date Estimator
Estimate the harvest date for your garden plants by adding days-to-maturity to the planting date.
How to use this tool
- Enter the date you planted or transplanted seedlings.
- Enter the days-to-maturity from the seed packet.
- The calculator returns the estimated harvest date.
Track your garden harvest window so you never miss peak ripeness.
Formula
Harvest Date = Planting Date + Days to Maturity
The planting date is advanced by the integer number of days-to-maturity using UTC calendar arithmetic, producing an ISO date string: YYYY-MM-DD.
How it works
This calculator adds a crop's days-to-maturity directly to the planting date using UTC date arithmetic, returning the earliest expected harvest window. Days-to-maturity figures are seed-packet estimates representing average time under good growing conditions; actual harvest may vary by one to two weeks depending on weather, soil fertility, and variety.
The result is a calendar date, not a countdown — it is most useful for scheduling successive sowings and planning storage or market timing.
Worked example
Worked example
- Planting date: 2025-05-01. Days to maturity: 70.
- Add 70 days to 1 May 2025: May has 31 days, leaving 30 days in May after the 1st, so 70 − 30 = 40 days into June and beyond.
- 30 remaining days take us to 31 May; 30 more take us to 30 June; the final 10 days reach 10 July.
- Result: 2025-05-01 + 70 days = 2025-07-10.
Estimated harvest date: 2025-07-10
Key terms
- Days to maturity
- The number of days from transplant or direct sowing to a crop's first harvestable stage, as stated on seed packaging under average conditions.
- UTC date arithmetic
- Date calculations performed in Coordinated Universal Time to avoid daylight-saving-time shifts that could add or drop a day near clock changes.
- Successive sowing
- Planting the same crop at intervals of a week or two so harvests are staggered rather than all arriving at once.
- Harvest window
- The span of days during which a crop can be picked at peak quality; most vegetables remain harvestable for several days around the estimated date.
Frequently asked questions
- How do I calculate harvest date from planting date?
- Add the days-to-maturity (from the seed packet) to the planting or transplant date. For example, planting tomatoes on May 1 with 70 days to maturity gives a harvest date around July 10.
- What does days to maturity mean on a seed packet?
- Days to maturity is the number of days from transplanting (or from germination for direct-sown crops) until the plant reaches harvestable size. It is an average — actual timing varies by weather and growing conditions.