The rapid growth of e-commerce has significantly changed the way customers search for, evaluate, and purchase products. Online shopping is available throughout the day, but customer activity may differ according to the time at which shopping takes place. This study focuses on a comparative analysis of online buying behaviour during peak hours and off-peak hours. The study examines differences in purchase frequency, spending, product selection, impulse buying, discount sensitivity, browsing time, and purchase intention across different periods of the day. A descriptive and analytical research design is adopted, with primary data proposed to be collected from online shoppers through a structured questionnaire. For illustration, the analysis considers a sample of 200 online customers, divided equally between peak-hour and off-peak-hour shoppers. The study indicates that peak-hour customers show comparatively higher purchase frequency, stronger responsiveness to promotional offers, and greater impulse-buying tendencies, while off-peak shoppers tend to spend more time comparing products and prices before completing purchases. Previous research also indicates that time of day can influence consumer decision-making and online marketplace behaviour. The study provides useful implications for e-commerce platforms and marketers in designing time-based promotions, personalized recommendations, and customer engagement strategies.