# Day & Zimmermann

**Canonical:** https://apis.io/providers/day-zimmermann/  
**Website:** https://www.dayzim.com  
**APIs profiled:** 0

Day & Zimmermann is a privately held, family-owned diversified industrial services company founded in 1901 and headquartered in Philadelphia, Pennsylvania. The company operates across four primary business segments — Maintenance & Construction (power, nuclear, fossil, renewable, and chemical plants), Munitions (ammunition manufacturing, storage, and demilitarization for the U.S. military, including operation of the Lake City Army Ammunition Plant), Government Services (security, EOD, facility management, and architecture/engineering for federal agencies), and Workforce Solutions (staffing and talent placement via Yoh). The Yoh family has controlled the company since 1961; Harold L. Yoh III serves as Chairman and CEO. Day & Zimmermann reported approximately $2.7 billion in revenue in 2023 with roughly 43,000–52,000 employees across approximately 150 global locations. Day & Zimmermann does not publish any public developer APIs; its business is delivered through long-cycle service contracts, government-owned contractor-operated (GOCO) facilities, and direct client engagements.

## Kin Score — 3.8 / 100 (minimal)

Scored 2026-08-20 under rubric 0.12.0. Trend: flat (+0.0 from 3.8).

| Facet | Score |
|---|---|
| Discoverability | 50.0 |
| Contract Quality | 0.0 |
| Governance | 0.0 |
| Contract Governance | 0.0 |
| Operational Transparency | 0.0 |
| Developer Ergonomics | 2.4 |
| Commercial Clarity | 0.0 |
| Access Clarity | 0.0 |

Regulatory layer — **Energy & Utilities**: 8.1 (matched via tags).

## Agent readiness — 0.0 (human-only)

| Dimension | Value |
|---|---|
| Spec Presence | no |
| Agentic Access | no |
| Reversibility Documented | no |
| MCP Server | no |
| Auth Clarity | no |
| Idempotency | no |
| Error Semantics | no |
| OpenAPI Examples | no |
| Rate Limit Signal | no |
| Event Surface Described | no |
| Agent Skills | no |
| Well Known Catalog | no |
| Consent Identity | no |
| Agent Card | no |
| Dry Run Mode | no |

## Access

Unknown — onboarding: unknown, pricing: unknown, trial: no (confidence: low).

## Security (1)

- **Day Zimmermann Domain Security** — TLSv1.3 · HSTS · DMARC

## Tags

Ammunition, Architecture and Engineering, Construction, Defense, Engineering Services, Government Services, Industrial Services, Maintenance, Munitions, Nuclear Services, Power, Staffing, Workforce Solutions

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Profiled by [API Evangelist](https://apievangelist.com) and published on [APIs.io](https://apis.io/providers/day-zimmermann/). Scores are computed from the provider's own public artifacts under a published rubric.