Which convention should I pick if my document just says thirty days?

Read the governing document closely for whether it specifies business days or calendar days. When genuinely unclear, calculating both and treating the later date as the safer planning target avoids understating the required notice.

Does this handle a notice period stated in weeks?

Enter the equivalent day count instead, such as 14 for two weeks, since the calculation is the same once expressed in days.

Notice Period End Planner

Calculate the end date of a stated notice period. Choose whether the count runs in calendar days, calendar months, or business days. This makes no determination about whether a specific notice period is legally sufficient for any lease, job, or contract.

Planning a payment term instead of a notice period? See Net Terms Invoice Planner.

Worked example

Thirty calendar days of notice given on January 1 ends January 31, a simple fixed count with the notice date itself treated as day zero rather than day one. One calendar month of notice given on January 31 constrains to February 28 in a non-leap year, since February has no 31st day for the month-add operation to land on, the same month-end rule covered in the calendar math resources. Thirty business days of notice given on the same date lands noticeably later than 30 calendar days, since every Saturday and Sunday along the way adds extra calendar time without adding to the business-day count itself.

Common mistakes

Confusing 30 calendar days with one calendar month. They only produce the same end date when the specific month involved happens to have exactly 30 days.
Assuming the notice start date counts as day one. Here it counts as day zero, so a 30-day notice given on January 1 ends on January 31, not February 1.

Limitations

This applies the exact count and convention entered. It makes no legal determination about statutory or contractual minimum notice requirements for any employment, lease, or service relationship in any jurisdiction.

Frequently asked questions

Which convention should I pick if my document just says thirty days?: Read the governing document closely for whether it specifies business days or calendar days. When genuinely unclear, calculating both and treating the later date as the safer planning target avoids understating the required notice.
Does this handle a notice period stated in weeks?: Enter the equivalent day count instead, such as 14 for two weeks, since the calculation is the same once expressed in days.