A printable civil month tool with week numbers, day counts, weekend highlighting and a clean report view around the CalculationTime clockface.
Inputs, result, proof and time.
Use the instrument above, then check the calculation record, assumptions and related tools below.
Calendar Builder
Build a printable month
CalculationTime Monthly Calendar
September 2026
Days
30
Visible Weeks
5
Weekend Days
8
ISO Weeks
36-40
ISO
Mon
Tue
Wed
Thu
Fri
Sat
Sun
36
31AugDay 243
1SeptDay 244
2SeptDay 245
3SeptDay 246
4SeptDay 247
5SeptDay 248
6SeptDay 249
37
7SeptDay 250
8SeptDay 251
9SeptDay 252
10SeptDay 253
11SeptDay 254
12SeptDay 255
13SeptDay 256
38
14SeptDay 257
15SeptDay 258
16SeptDay 259
17SeptDay 260
18SeptDay 261
19SeptDay 262
20SeptDay 263
39
21SeptDay 264
22SeptDay 265
23SeptDay 266
24SeptDay 267
25SeptDay 268
26SeptDay 269
27SeptDay 270
40
28SeptDay 271
29SeptDay 272
30SeptDay 273
1OctDay 274
2OctDay 275
3OctDay 276
4OctDay 277
Notes
Appointments, deadlines, bills, trips and reminders.
Assumptions
Gregorian calendar, local browser date rules, monday week start, visible range 2026-08-31 to 2026-10-04.
Monthly Output Room
Make the month sheet inspectable and print-safe
The tabs keep the weekday layout, print controls, boundary assumptions and source notes together so the page stays auditable.
Month construction
Month sheets are built from local Gregorian date stepping
CalculationTime creates a grid based on the selected year, month and week start, then fills all visible cells from local noon.
Leading/trailing cells preserve the calendar shape and weekday alignment.
Weekend markers use the selected calendar preferences.
ISO week labels are computed from the same date objects and month context.
year + month + weekStart -> month grid, ISO week labels, note sheet
Method
The grid is calculated from local Gregorian dates
The tool builds each visible cell from JavaScript Date objects at local noon to avoid midnight daylight-saving edge cases. It then labels ISO weeks from the Thursday rule and day-of-year counts from the difference between local noon on the date and local noon on January 1.
Week starts
Sunday and Monday starts change the leading offset only. The actual dates and ISO week labels stay the same.
Print path
The print button opens the browser print dialog and the print stylesheet hides controls while keeping the month grid, notes and assumptions.
Limits
Public holidays, school terms and lunar events are intentionally not inferred here. Those belong on their own sourced calendar pages.
Source Notes
Standards and platform basis
The page uses the proleptic Gregorian calendar exposed by browser JavaScript Date objects and labels ISO week numbers using the ISO 8601 week-date convention where week 1 is the week containing the year's first Thursday.