What comes out
The 1st through the last day of the month laid out in seven columns, with the leading and trailing boxes greyed. Row height is worked backwards from the sheet: take the paper height, subtract half-inch margins top and bottom, subtract the heading and the weekday strip, and divide what is left by the number of rows the month needs. A month that fits in five rows gets taller boxes than one that spills into six. That is why a February that starts on a Sunday prints with the biggest boxes of any month in a non-leap year — 28 days from a Sunday is exactly four rows.
The number of rows is not fixed and it changes with the week start. August 2026 begins on a Saturday: starting weeks on Sunday it needs six rows, and starting them on Monday it still needs six. A month beginning on a Sunday with 31 days needs five rows on a Sunday start and six on a Monday start. If your boxes came out short, flipping the week start is worth one click before you reach for a smaller font.
Box height and writing lines
"Fill the sheet" pushes the grid to the bottom margin, which is what you want for a wall or fridge calendar where several things get written in a day. "Leave room at the bottom" shrinks the boxes to about 60 percent and gives back the space, which suits a desk calendar where the month is a reference and the list underneath is the real content. The notes block adds a ruled strip below the grid for that list.
Writing lines are faint horizontal rules inside every box, spaced 5.5 mm apart, and the tool fits as many as the box height allows. They help if you are writing at a desk and hurt if the calendar is on a wall being read from across the room, because they compete with the entries. Off is the better default for anything you will look at from more than a few feet.
About the holidays it marks
The federal list is computed from the rules rather than looked up in a table, so it is right for any year you print: the third Monday in January, the last Monday in May, the fourth Thursday in November, and so on. Fixed-date holidays that land on a Saturday are marked on the Friday before and ones that land on a Sunday on the Monday after, which is what the federal observed calendar does and what most banks follow.
That list is not your list. States add their own days, school districts run a calendar nobody else uses, and plenty of private employers work Columbus Day and Veterans Day while closing the Friday after Thanksgiving, which is not a federal holiday at all. Treat the marks as a starting point and put your own closures in the second box, one per line as a date and a label. Anything you type there wins over the federal name for the same day.
Printing it so it looks like the preview
The print button opens the calendar as its own page and calls the print dialog. Three things in that dialog change the output. Orientation has to match what you picked here, and browsers do not always inherit it. Scale should stay at 100%; "fit to page" shrinks the grid and leaves a band of white at the bottom. Background graphics are off by default in every major browser, so the pale grey on the out-of-month boxes and the weekday header will not print until you turn that option on — the grid lines and the numbers print either way, so this is cosmetic.
Margins are set to half an inch in the page itself. If your printer cannot reach that close to the edge it will clip, and the fix is to set margins to "default" in the dialog rather than "none". Turning off headers and footers stops the browser printing the date and URL across the top of your calendar.
Questions people ask
Can I print a whole year at once?
One month per run. Change the date to the next month, press the button again and print — the settings stay put, so twelve sheets come out identical apart from the grid. There is no year-at-a-glance layout here because the boxes would be too small to write in, which is the only reason to print a calendar rather than look at one on a phone.
Why is there no Saturday start?
Sunday and Monday cover essentially every calendar printed in English. A Saturday start would change the row count for some months and would confuse anyone else reading the sheet on your wall.
The holiday names run into the date numbers.
Long labels wrap to the right of the box under the number. If a name you typed is long, shorten it — "Closed" reads fine at 8.5 points and "Annual inventory and stocktake" does not. Federal names are already abbreviated for this reason.
Does it handle leap years?
Yes. February 2028 comes out as 29 days ending on a Tuesday, and the grid is built from the real day-of-week of the 1st rather than from any assumption about month lengths.