Period Calendar

A 13-period, 4-week calendar docked to your browser corner, with per-date notes. Works fully offline.

Many teams don't plan by month - they plan in four-week periods. If your work runs on a 13-period fiscal calendar (13 periods x 4 weeks, Sunday-to-Saturday), it's easy to lose track of exactly where you are: which period, which week, how many days until the next one starts. Period Calendar solves this by keeping that context visible while you browse, without getting in your way. Key features: - Always-on glance view: a small, unobtrusive label docked in the bottom-right corner of your browser shows exactly where you are right now - period, week, and date (e.g. "P7W4 Jul 8") - no clicking required. - One-click full calendar: click the label to expand a full period calendar, so you can navigate forward and backward through periods and weeks, check upcoming period boundaries, and plan ahead. - Built for period-based planning: designed specifically around the 4-week period rhythm many businesses use for reporting, sprints, and reviews - instead of forcing your fiscal structure into a regular monthly calendar. - Handles leap weeks automatically: in years with a 53rd week, Period 13 correctly extends to a 5th week (P13W5) instead of miscounting - so the calendar stays accurate year after year. - Lightweight and unobtrusive: sits quietly in the corner of your screen and stays out of your way until you need it. Whether you're closing out a period, planning next week's priorities, or just need a quick answer to "what week are we in," Period Calendar keeps that structure one glance - or one click - away.