# Blog - Raju Prasai

Technical blog by Raju Prasai, Project Manager and Senior .NET Engineer from Nepal.

URL: https://rajuprasai.com.np/blog/

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## About

Engineering notes on Bikram Sambat calendar math, nepali date converter, C#, .NET, and open-source software from Nepal.

**Author:** Raju Prasai - Project Manager & Senior .NET Engineer, Jhapa, Nepal
**Portfolio:** https://rajuprasai.com.np/
**GitHub:** https://github.com/RajuPrasai

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## Articles

### NepDate Widget: The Nepali Calendar Desktop App Windows Never Shipped

URL: https://rajuprasai.com.np/blog/nepdatewidget-nepali-calendar-windows.html
Published: 2026-06-02
Tags: NepDate Widget, nepali calendar, nepali patro, Bikram Sambat, Windows, Preeti
Read time: 9 min

Windows has no Bikram Sambat awareness. Every Nepali Windows user navigates a daily gap - BS dates, legacy fonts, unit conversions - that the OS never filled. NepDate Widget is a free WPF app covering a full Bikram Sambat calendar with tithi and holidays, a Preeti-to-Unicode converter, a hotkey launcher, batch image processing, and more, almost all offline in the taskbar.

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### Nepali Date Arithmetic in .NET: AddDays, AddMonths, and Date Ranges

URL: https://rajuprasai.com.np/blog/nepali-date-arithmetic-ranges.html
Published: 2026-06-02
Tags: Bikram Sambat, nepali calendar, nepali date converter, NepDate, .NET, C#
Read time: 8 min

Converting between BS and AD is step one. The harder work is everything after: computing a 30-day probation end, building a fiscal year report window, checking whether a transaction date falls within an allowed period. This post covers AddDays, AddMonths, AddYears, NepaliDateRange, and SmartDateParser with verified code examples.

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### How Bikram Sambat Calendar Math Works in .NET

URL: https://rajuprasai.com.np/blog/bikram-sambat-calendar-math.html
Published: 2026-06-01
Tags: Bikram Sambat, nepali calendar, nepali date converter, NepDate, .NET, C#
Read time: 10 min

The Bikram Sambat calendar cannot be converted to Gregorian with a formula. Month lengths are 29 to 32 days, determined by solar transits, not a fixed pattern. This post explains the lookup-table approach, the fiscal year math, and how the NepDate library handles it in .NET with O(1) performance and zero heap allocations.

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## Related

- NepDate .NET Library: https://nepdate.rajuprasai.com.np/
- NepDate Widget: https://nepdatewidget.rajuprasai.com.np/