Here are two methods to filter data by day of the week or month in Excel:

Method 1: Using the Filter Dropdown Menu (Works for both Day of Week and Month)

1. Select your data range: Ensure the column containing your dates is included in the selection.
2. Activate the Filter: Go to the "Data" tab and click the "Filter" button in the "Data Tools" group. Filter arrows will appear on the header row of your data.
3. Click the filter arrow for the date column: A dropdown menu with filtering options will appear.
4. Filter by Day of Week or Month:
- Day of Week: There will be options for each day (Monday, Tuesday, etc.). Select the desired day(s) to filter your data.
- Month: Choose "Number Filters" followed by "Months" from the dropdown menu. Select the specific month(s) to filter by.
5. Click OK (Optional): Depending on your Excel version, you might need to click "OK" to apply the filter.

Method 2: Using the TEXT and MONTH Functions (For Day of Week Only)

1. Create a helper column: In an adjacent column, enter a formula to extract the day of the week from your date data. In cell B2 (assuming your dates are in column A), you can use the formula: `=TEXT(A2,"ddd")`. This will display the abbreviated day name (Mon, Tue, etc.)
2. Filter the helper column: Apply a filter to the newly created helper column and select the desired day(s) of the week. This will indirectly filter your main data based on the day of the week.

Note: The first method is simpler and more user-friendly, while the second method offers more flexibility if you need to perform additional calculations based on the day of the week.