- The calendar turned into a small grid of months and a warning says "Showing month level".
- The Date field well holds a date hierarchy that has been collapsed above days, so Power BI only sends year, quarter or month values and the visual falls back to a Year × Month matrix. In the Date field well, open the field's menu and choose the date column itself instead of Date Hierarchy, or keep the hierarchy and make sure its Day level is included. The day-level calendar comes back as soon as days arrive.
- Some days are an empty colour, not the lowest colour, and the per-day average looks too high.
- Those days have no value. When a measure is blank for a day, Power BI sends no number for it, and the visual draws that day in Colours > No-data colour and leaves it out of Per day, the weekday profile and streaks. A day with a real 0 is a value: it is coloured at the bottom of the scale and counts in the average. If a blank genuinely means zero in your data, return 0 from the measure for the dates you have data for (for example [Total Sales] + 0 limited to your first and last data date); if it means "not reported", leave it blank so the gap stays visible.
- The punch card shows Weekday × Month and says "Weekday × Hour needs times of day".
- The Date field carries dates without a time, so there is no hour to place. Bind a date/time column (such as the ticket's opened timestamp) to Date, or add a whole-number column named Hour (0 to 23) to the Date field well next to the date. Matrix > Rows × columns = Weekday × Hour then draws the punch card, and Matrix > Hour labels switches between 24-hour and 12-hour.
- Daily values are far higher than the same measure in a table visual.
- A date/time column on Date gives one row per timestamp, and the visual combines the rows of a day with Colours > Combine rows per cell, which is Sum by default. That is right for counts and amounts, but an average or a ratio measure gets added up. For the calendar views, bind a date-only column so Power BI evaluates the measure per day, or choose Average, Minimum or Maximum under Combine rows per cell if that is what the day should show. The same applies when extra fields on Notes or Holidays split a day into several rows.
- One extreme day makes the rest of the year look the same pale colour.
- Colours > Smart range (ignore extreme 2 %) is on by default and caps the top and bottom 2 % of values once there are at least 20 days. If the year is still washed out, set Colours > Scale to Quantile (outlier-proof), so each colour step holds the same share of days, or Logarithmic for values that span orders of magnitude (zero and negative days sit at the bottom of a logarithmic scale). Scale minimum and Scale maximum fix the range by hand.
- Weeks start on the wrong day, or the week numbers do not match our finance calendar.
- The columns of the year strip follow Calendar > Week starts on (Monday, Sunday or Saturday). Week numbers are a separate setting: ISO 8601 numbers weeks the ISO way (Monday weeks, week 1 holds the year's first Thursday) whatever the start day, while Week of 1 January = 1 counts weeks from 1 January using your chosen start day. For a fiscal year, set Year type to Fiscal year and check Fiscal year starts in, which defaults to July.
- Report readers see one merged calendar and plain value colours, while I see small multiples and target colours.
- Comparison colouring, small multiples, retail 4-4-5 years, measure switching, unusual-day detection and rules on target, attainment, prior year or unusual days are premium. In edit mode they all preview in full; a reader without a licence gets a working calendar with the free features (value colours, one calendar with all data, fiscal months instead of retail periods) and a single notice from Power BI. Nothing is blocked or watermarked. To give a reader the premium view, assign them a SmartVisuals Calendar Heatmap licence in the Microsoft 365 admin center under Billing > Licenses.
- My chosen colours and rule fills disappear in Windows high contrast mode, or I cannot reach days with the keyboard.
- In a high-contrast theme the visual uses the host's colours on purpose: colour pickers and Fill the cell with the colour are ignored, cells are outlined, and badges, notes, holidays and unusual days keep their shapes so no meaning depends on hue. For the keyboard, press Tab to move focus into the calendar, use the up and down arrows to move by day and left and right to move by week (in the matrix view the arrows move cell by cell), Enter or Space to select the focused day (Ctrl adds to the selection), Home and End to jump to the first and last day, and Escape to clear the selection.
