Use Cases

This section covers common patterns and real-world use cases for the Nepali Date Library in Python.

Overview

The library is designed to handle various date-related tasks in Python applications contexts:

Use Case	Description	Link
Date Conversion	Converting between AD and BS dates	→ Date Conversion
Calendar Generation	Building datepickers and calendars	→ Calendar Generation
Fiscal Year Operations	Working with Nepal's fiscal year	→ Fiscal Year
Date Ranges	Working with week/month/year boundaries	→ Date Ranges

Common Scenarios

Web Applications (Django/Flask/FastAPI)

• User registration with Nepali date of birth
• Event scheduling in Nepali calendar
• Report generation by Nepali dates
• Bill and invoice dating

Data Processing & Scripts

• Batch converting database rows containing Nepali dates
• Formatting dates for data analysis
• Fiscal year aggregations for financial data

General Business Logic

• Fiscal year financial reports
• Quarterly statements
• Tax period calculations
• Payroll processing

Quick Examples

Display Today's Date in Nepali

from nepali_date_library import NepaliDate

today = NepaliDate()

# Full Nepali format
print(today.format("dddd, mmmm dd, yyyy"))
# Output: बुधबार, माघ ०१, २०८२

# Mixed format
print(today.format("MMMM DD, YYYY (dddd)"))
# Output: Magh 01, 2082 (बुधबार)

Convert API Dates

from nepali_date_library import ADtoBS

# Simulated response from an API with Gregorian date
api_response = {"created_at": "2026-01-14T10:30:00Z"}

# Extract the date part and covert to Nepali date for display
nepali_date = ADtoBS(api_response["created_at"].split("T")[0])
print(f"Created on: {nepali_date}") # Created on: 2082-10-01

Age Calculation

from nepali_date_library import NepaliDate

def calculate_age(birth_date: str) -> int:
    dob = NepaliDate(birth_date)
    today = NepaliDate()
    # Calculates full years elapsed
    return today.diff(dob, "year")

print(calculate_age("2050-05-15")) # e.g. 32

Date Validation

from nepali_date_library import NepaliDate

def validate_nepali_date(year: int, month: int, day: int) -> bool:
    # month is 1-indexed here natively for user inputs
    return NepaliDate.is_valid(year, month, day)

# Validate user input
user_year = 2082
user_month = 10 # Magh
user_day = 32

if validate_nepali_date(user_year, user_month, user_day):
    print("Valid date")
else:
    print("Invalid date") # e.g. Day too high for Magh if it only has 29 days