Today I tackled one of our most challenging technical issues: properly handling date overlaps and partial day leaves in our shift management system. This required careful attention to edge cases and a deep understanding of how dates interact across our platform.
The core problem was ensuring our system could correctly identify and handle situations where approved leaves partially overlap with scheduled shifts. For example, if an employee has a shift from 8am to 5pm, but has approved leave starting at noon on the same day, the system needs to intelligently manage this partial overlap rather than simply marking the entire shift as “On Leave.”
I started by enhancing the leave detection algorithm to identify these partial overlaps. The solution required comparing not just dates but specific timestamps to determine exactly how leaves and shifts intersect. I implemented logic that categorizes overlaps into several types:
- Complete overlap (leave covers the entire shift)
- Partial start overlap (leave covers the beginning portion of a shift)
- Partial end overlap (leave covers the ending portion of a shift)
- Middle overlap (shift spans across multiple leave days)
For each type of overlap, I created specific handling procedures. When a partial overlap is detected, the system now generates appropriate notifications and visual indicators that clearly show exactly which portions of a shift are affected by leave. This required modifying both the data model and the UI components to accommodate these more nuanced states.
The most challenging aspect was handling timezone inconsistencies between different parts of the system. Since leave requests might be entered in one timezone while shifts could be viewed in another, I implemented universal timestamp conversions that ensure consistent date comparisons regardless of user location. This involved standardizing all date handling functions to use UTC internally, then converting to local time only for display purposes.
I also improved the leave request form to support specifying partial day leaves with start and end times, rather than just full days. This enhancement gives employees and managers more flexibility when scheduling time off, allowing for appointments or personal matters without requiring full-day absences.
To verify these changes worked correctly, I created a comprehensive test suite with various overlap scenarios. I checked that partial leaves were correctly reflected in the shift calendar, that notifications were sent to appropriate stakeholders, and that reports accurately tracked these nuanced attendance patterns.
These refinements to our leave management system create a more flexible, accurate platform that better reflects the reality of modern workplace scheduling. Employees can now take the exact time they need without wasting unused leave hours, while managers gain clearer visibility into staffing levels throughout each day.