Everything on this page is plain calendar math, computed in your browser. Each person's rotation is laid onto the real calendar for the year, day by day, and a day counts as off together when neither of you has a shift. Nothing is estimated and nothing leaves the page. To study one pattern on its own, the shift pattern visualizer draws a single rotation with the same math.
A night shift starts on its calendar day and ends the next morning. Two definitions follow from that. A recovery day is the first day off after a night shift: one of you spends that morning asleep, so shared days like that are counted, then called out separately. A full shared weekend means no shift from either of you touches Saturday or Sunday, and a Friday night that ends Saturday morning breaks it.
Where each of you sits in your rotation changes everything, so both patterns take an anchor date: day 1 of any on-block you can remember. Set it and the rest of the year falls into place. The download button draws the calendar exactly as shown here, so anything you share can be reproduced on this page.
Yes. Neither of you is at work, so the day counts. But the first day off after a night shift starts with one of you asleep, so the calculator also tells you how many of your shared days are recovery days for at least one of you. Plan the afternoon, not the morning.
A night shift that starts Friday ends Saturday morning. Saturday is technically a day off, but half of it goes to sleep. A weekend only counts as fully shared when no shift from either of you touches Saturday or Sunday.
Two fixed Monday to Friday schedules share all 52, which is the baseline. Once one of you rotates, the biggest lever is phase: two people on the same 4 on 4 off rotation with the same start date share every day off, while the same two patterns out of step can share almost none. Try moving one anchor date a few days and watch the numbers change.
It is day 1 of a block of shifts, and it sets where each of you sits in the rotation. Pick any date you know one of you started an on-block, in any month. Monday to Friday and weekend-only patterns ignore it because they are locked to weekdays.
No. This page draws idealized patterns, and real rosters have swaps, overtime, and exceptions. Reading a real schedule is what the Lumical app does: photograph the roster and every shift lands in your calendar, overnights included. We make both, which is why this tool is free.