Gantt Chart and Project Timeline Creator

Help me create a Gantt chart in Excel:

**Project Details:**
- Project name: [your project]
- Number of tasks: [approximate]
- Timeline duration: [weeks / months]
- Start date: [project start]

**Task Information Available:**
- [ ] Task names
- [ ] Start dates
- [ ] End dates or durations
- [ ] Dependencies between tasks
- [ ] Assigned resources
- [ ] Completion percentage
- [ ] Milestones

**Chart Features Needed:**
- [ ] Automatic date scaling
- [ ] Color coding by status/resource
- [ ] Progress indicators
- [ ] Today line marker
- [ ] Milestone markers
- [ ] Weekend/holiday highlighting
- [ ] Dependency arrows

**Data Sample:**
| Task | Start | Duration | Assigned | Status |
|------|-------|----------|----------|--------|
| [Task 1] | [Date] | [Days] | [Name] | [Status] |
| [Add more] | | | | |

**Interactivity:**
- Update automatically with data changes: [Yes/No]
- Filtering capability: [Yes/No]
- Zoom in/out on timeline: [Yes/No]

Please provide:
1. Data structure setup
2. Conditional formatting approach for bars
3. Formulas for date calculations
4. Step-by-step chart creation
5. Formatting for professional appearance
6. Maintenance tips