Days From a Date Calculator

Dates counted from the start date

Counting days looks trivial and is frequently got wrong, particularly for contractual deadlines and statutory periods expressed in days — months have different lengths, leap years intervene, and there is always the question of whether the first day counts.

This tool counts both total days and weekdays, and shows you the calendar dates on which 30, 60, 90 and 180 days fall. If you live in Thailand on a long-stay visa, those last two numbers will be familiar: 90 days is the immigration reporting cycle, and 180 days is the tax residency threshold.

How this tool counts. It counts elapsed days between two dates, without counting the start day twice. From the 1st to the 2nd is one day. This matches how ages and ordinary durations are counted.

Be aware that some laws and contracts count inclusively, which gives a figure one day higher. For anything with legal consequence, check the counting method specified in the document itself.

Weekday counts exclude Saturdays and Sundays. They do not deduct Thai public holidays, because the list is announced annually and differs between government offices, banks and the private sector. For a contractual deadline, check that year’s holiday calendar as well.

Years can be entered in either calendar. Anything from 2400 upwards is read as a Thai Buddhist year and converted automatically, so you can type dates straight off a Thai document.

Day counts that matter in Thailand

90 days is the reporting cycle for foreigners on long-stay visas, who must notify Immigration of their address. It runs from the most recent entry into the country or from the previous report, whichever is later.

180 days is the threshold the Revenue Department uses to decide tax residency. Spend 180 days or more in Thailand within one calendar year and you are a Thai tax resident, which brings foreign income you bring into Thailand into scope. Note that income earned from work performed in Thailand is taxable regardless of how many days you spend here.

Counting the 180 days accurately matters if you are near the line. Days of arrival and departure both generally count as days present, so a pattern of short trips adds up faster than people expect.

30, 60 and 120 days are the payment terms that appear most often in commercial contracts.