Nepal's Muslim population, roughly 4-5% of the national total, is concentrated overwhelmingly in the Terai — the flat southern strip bordering India's Bihar and Uttar Pradesh states — where Madhesi Muslim communities share close linguistic and cultural ties with neighboring Indian districts. Kathmandu's own Muslim history runs on a separate, older track: Kashmiri Muslim traders arrived during the Malla dynasty period, drawn by the valley's position on trans-Himalayan trade routes, and their small community remains distinct from the much larger Terai population even today.
Kathmandu sits at over 1,300 meters elevation in a mountain valley, unlike the near sea-level plains where most Nepali Muslims actually live, so a schedule calculated specifically for the capital's altitude and coordinates will differ measurably from one calculated for a Terai city like Biratnagar or Nepalgunj.
Nepal is assigned the University of Islamic Sciences, Karachi method here, reflecting the Terai region's deep cultural and geographic ties to the Indian subcontinent, where this calculation standard originated and remains widely used.
Because Nepal's Muslim population is overwhelmingly concentrated in the Terai, an extension of the Gangetic plain culturally and geographically continuous with northern India, the Karachi-based method common across the subcontinent fits better than a global standard.
Yes, modestly — sitting over 1,300 meters above sea level shifts the horizon slightly compared to sea-level cities at the same latitude, a small but real factor in precise sunrise, Maghrib and Fajr calculations.
Not historically — Kathmandu's Muslim residents descend largely from Kashmiri trading families who settled the valley centuries ago, while the much larger Terai Muslim population has closer ties to neighboring districts of India.
Kathmandu sits roughly a degree further north and at much higher elevation than Terai cities, so its Fajr and Isha times can differ from Biratnagar's by several minutes even on the same date.