docs: Add date operators to property filter operators reference

contents/docs/data/property-filters.mdx

@@ -43,6 +43,23 @@ Presence operators check whether a property exists on a person or event, regardl
 | `is set` | Matches when the property exists and has any value |
 | `is not set` | Matches when the property does not exist or has no value |
 
+## Date operators
+
+Date operators filter based on when something occurred relative to now or compared to a specific date.
+
+| Operator | Description |
+|----------|-------------|
+| `is date before` | Matches when the date is before the specified value |
+| `is date after` | Matches when the date is after the specified value |
+
+Date operators accept the following value formats:
+
+- **Relative dates** – A number and unit offset from now: `-7d` (7 days ago), `30d` (30 days from now), `-1h` (1 hour ago), `-1w` (1 week ago), `-1m` (1 month ago), `-1y` (1 year ago)
+- **ISO 8601 dates** – Standard date format like `2024-01-15`
+- **ISO 8601 datetimes** – Date with time and optional timezone like `2024-01-15T10:30:00Z`
+
+> **Note:** Relative date values with magnitudes of 10,000 or greater (e.g., `10000d`) are rejected as invalid to prevent overflow errors.
+
 ## Semver operators
 
 Semver (semantic versioning) operators are additional operators available on string properties that compare values as version strings (e.g., `1.2.3`) instead of plain text. There is no separate semver data type – these operators appear alongside the regular string operators in the filter dropdown, labeled with a `(semver)` suffix.