Tourist visas commonly grant stays of 30, 60, or 90 days, depending on the country's regulations and bilateral agreements. Many allow single or multiple entries within the visa's validity period. If you wish to stay longer, some countries permit extensions through immigration services; however, this process involves applying before your visa expires and may require additional fees and justification. Overstaying a visa is a serious offense that can lead to fines, deportation, detention, or a ban on re-entry, sometimes lasting years. Immigration authorities may record overstays, affecting future visa applications. It's crucial to track your authorized stay accurately, understand local regulations, and seek extensions proactively when needed to maintain good legal standing during international travel.