Opportunity brief
Where the OpenBuild Journey Becomes Reality # Builders Day
Builders Day by [HackUnion](https://hackunion.in) is the culmination of the [OpenBuild Week](https://hackunion.in/obw) journey, a space where builders come together to collaborate, solve problems, build products, and compete.
From learning to building. From ideas to prototypes. From campus communities to one Builders Day.
**This is where builders come to build.**
## Before You Join
Builders Day is not about starting your project from scratch on the final day.
Projects can be developed from **28 July to 26 September**, with the final submission deadline at **3:00 PM IST on 26 September**.
Whether you're bringing an MVP from the OBW Campus Series or building independently, come prepared with a working product. We recommend having your project **~95% complete before Builders Day**.
Use the final day to **improve, test, scale, polish, network, showcase your work, and celebrate what you've built.**
Your project will be evaluated on:
- **Accessibility**
- **Working Product**
- **Purpose & Scalability**
- **Pitching**
### Read the Hackathon Guide Before You Start
We've put together the **Builders Day Participant Guide** with everything you need to know — eligibility, project requirements, development timeline, judging criteria, submissions, AI and tool usage, team participation, prizes, final-day expectations, and the submission checklist.
**📖 Read the complete Hackathon Guide → [HACKATHON GUIDE LINK](https://drive.google.com/file/d/1E94z4u54nHiUxBpw96l-DLpnb-3EEDcx/view?usp=sharing)**
**Read it. Prepare your project. Then come ready to build.**
## Builders Day
**26 September 2026**
**Build it. Ship it. Show what it can become.** No Restrictions