California · Nonprofit
Harbor Day Endowment Corporation
Harbor Day Endowment Corporation (California) receives grants from 16 organizations whose IRS filings report $6,336,050 to it, the largest being THE WILLIAM JEFF AND JENNIFER GROSS FAMILY FOUNDATION ($3,800,000). 10 of them have funded it in more than one year.
Against its field
Harbor Day Endowment Corporation's funding base is broadening — from 1 funders to 8 as grant income climbed.
this organization peer median middle 50% of peers· 9,072 education nonprofits $1M–$10M, FY2025
Three funders worth looking at
Grantmakers with no record of funding this organization, ranked by how strongly the co-funder graph and the mission embeddings agree. The evidence is in section 03.
- The Devto Support Foundationshared funderslocal
- The Sumner Scholarship Endowment Foundation Incportfolio match
- Hattie a and Fred C Lynam Trustportfolio match
The organization over time
Each line starts at 100 in 2017, so what you read is the shape rather than the size: 150 means half as much again as 2017, 50 means half. The number beside each label in the key is where it ended. The shaded band is where the middle 50% of its peers' revenue would sit, given their growth.
How it's funded, over time
Each bar is one year's revenue split into where it came from, and every bar is the same height — these are shares, not amounts, so a year that raised twice as much looks the same size. Hover a bar for the split.
73% of Harbor Day Endowment Corporation’s revenue is contributions — more donation-reliant than the typical peer (48% for the typical peer).
Surplus & reserves
Operating surplus or deficit each year, and months of liquidity in hand. 4 of the last 9 reported years ran a deficit.
reserve
Who funds it, year by year
2017 → 2023: the base broadened from 1 funder to 8 funders, grant income rose $10k → $524k.
5 of 16 of your funders are donor-advised or pass-through sponsors (tagged DAF) — 30% of grant dollars received. That money is really individual donors directing a sponsor; the institutions to cultivate are the non-DAF funders.
From the IRS filings of Harbor Day Endowment Corporation’s funders (the co-funder graph). Association, not causation. Trends are read to FY2023, the last fiscal year that has finished arriving. FY2024–FY2026 are still being filed and are shown unshaded; they do not move any figure on this page.
How concentrated its funding is
Harbor Day Endowment Corporation leans on a few funders — its largest provides 60% of grant income and the top three 83%; half comes from just 1 funder.
the vertical line marks half of all grant income — 1 funder to its left
30% of the income these shares are computed over arrives through pass-through sponsors or from payers whose filings do not say what kind of payment it is. Concentration is still measured over all of it, because the money is real; what it does not support is a claim about how many institutions have chosen to fund Harbor Day Endowment Corporation.
Largest funder’s share by year: 2017 100% · 2018 99% · 2019 90% · 2020 81% · 2021 67% · 2022 43% · 2023 38% — diversifying over time.
“Effective funders” = inverse Herfindahl index (1 / Σ shareᵢ²) — the number of equal-sized funders that would give the same concentration. Trends are read to FY2023, the last fiscal year that has finished arriving. FY2024–FY2026 are still being filed and are shown unshaded; they do not move any figure on this page.
How long its funders stay
57% of Harbor Day Endowment Corporation's funders are still giving 3 years after their first grant; 63% give in more than one year at all.
Share of funders still giving k years after their first recorded grant, pooled across every acquisition cohort. A funder counts as retained in a year only if it made a grant that year. Measured to FY2023, the last fiscal year that has finished arriving — a funder cannot be counted as lapsed in a year most filers have not reached.
Where its funders are
97% of Harbor Day Endowment Corporation's grant income comes from California funders.
In-state vs out-of-state, by year
Funder states come from each funder’s own filing. $1.9M arriving through sponsors registered in 5 states is excluded from the map and the split above: a sponsor holds money on a donor’s behalf, so its registered address would place those dollars somewhere no donor need ever have been. Trends are read to FY2023, the last fiscal year that has finished arriving. FY2024–FY2026 are still being filed and are shown unshaded; they do not move any figure on this page.
Funders to approach
Grantmakers that don’t fund you yet, surfaced two ways: they back organizations that share your funders, or their grantees resemble your mission. The ones both signals agree on come first. Your 16 funders put you under-funded among the 341 organizations that share them.
- The Devto Support Foundationshared funderslocalCA · backs 33 organizations that share your funders · funds 119 organizations near you
- The Sumner Scholarship Endowment Foundation Incportfolio matchits grantees resemble your mission
- Hattie a and Fred C Lynam Trustportfolio matchits grantees resemble your mission
- Newburyport Bank Charitable Foundation Incportfolio matchits grantees resemble your mission
- Boston Schools Fundportfolio matchits grantees resemble your mission
- Block Island Maritime Funding Incportfolio matchits grantees resemble your mission
- Souder Family Foundationportfolio matchits grantees resemble your mission
- Anne Hampton Foundationportfolio matchits grantees resemble your mission
- Joshua Levine Memorial Foundationportfolio matchits grantees resemble your mission
- Homer Family Foundationportfolio matchits grantees resemble your mission
- Susan & George Craig Family Foundation Incportfolio matchits grantees resemble your mission
- Palmer Walbridge Foundationportfolio matchits grantees resemble your mission
From the co-funder graph (funders backing at least two comparable organizations, shrunk for grantee count, donor-advised and mega-funds excluded) and the universe embeddings. A research starting point; overlap is association, not a guarantee of fit.
Organizations like Harbor Day Endowment Corporation
Nonprofits whose mission and program text most resemble this one, by semantic similarity over the universe of US filings — the closest peers, and often the clearest route to shared or prospective funders.
In California
Nationally
Read directly from this organization’s own Form 990, as neutral context.
Where the money goes
99% of spending goes to programs.
Governance
Footprint & structure
Files a return copy in 1 state
Part of a family of 2 related entities
- 1960 Port Albans LLC · disregarded
- Harbor Day School · exempt
Screen this organization
A dated, signed PDF of the compliance screen for Harbor Day Endowment Corporation: IRS status (Business Master File, Publication 78, auto-revocation), the OFAC sanctions lists, the Internal Revenue Bulletin, and California registration, with the Rev. Proc. 2018-32 §8.01 reliance elements stated element by element. Generated from the current files at the moment you download it.
Screens are triage, not determinations; a source that cannot be read reports not screened, never clear. How the screen works · on the API as GET /api/screening/{ein}?format=pdf
Questions and answers
- Who funds Harbor Day Endowment Corporation?
- Harbor Day Endowment Corporation (California) receives grants from 16 organizations whose IRS filings report $6,336,050 to it, the largest being THE WILLIAM JEFF AND JENNIFER GROSS FAMILY FOUNDATION ($3,800,000). 10 of them have funded it in more than one year.
- How many funders does Harbor Day Endowment Corporation have?
- IRS filings report 16 organizations giving $6,336,050 in grants to Harbor Day Endowment Corporation, 10 of which have funded it in more than one year.
- Who is the largest funder of Harbor Day Endowment Corporation?
- THE WILLIAM JEFF AND JENNIFER GROSS FAMILY FOUNDATION is the largest funder on record, with $3,800,000 in grants. The full list of funders is on this page.
- How can an organization like Harbor Day Endowment Corporation find more funders?
- Start with the funders already giving here, then look at the foundations that back similar organizations in California. The funding by cause and by state pages list the largest funders for a given area and how to approach them.
These figures are read directly from IRS Form 990 / 990-PF e-file XML: this organization’s own return for FY2025 (financials across 2017–2025), and the filings of 16funders that report grants to it. “On record” means captured in the filings we have parsed — a funder that does not e-file, or whose grant detail is not itemized, will not appear. Filings run roughly 12–24 months behind. Trends on this page end at FY2023, the last fiscal year that has finished arriving; later years are shown and marked, and move no figure. Data on this page was exported August 27, 2026. What this page cannot tell you · view filing