Dates

Filter

This filter identifies dates such as May 22, 2014 in text. The supported date formats are:

Format	Example
yyyy-MM-d	2020-05-10
MM-dd-yyyy	05-10-2020
M-d-y	5-10-2020
MMM dd	May 5 or May 05
MMMM dd, yyyy	May 5, 2020 or May 5 2020

Required Parameters

This filter has no required parameters.

Optional Parameters

Parameter	Description	Default Value
`dateFilterStrategies`	A list of filter strategies.	None
`enabled`	When set to false, the filter will be disabled and not applied	`true`
`ignored`	A list of terms to be ignored by the filter.	None
`onlyValidDates`	When set to true, only valid dates will be filtered.	`false`

Filter Strategies

The filter may have zero or more filter strategies. When no filter strategy is given the default strategy of REDACT is used. When multiple filter strategies are given the filter strategies will be applied in order as they are listed. See Filter Strategies for details.

Strategy	Description
`REDACT`	Replace the sensitive text with a placeholder.
`RANDOM_REPLACE`	Replace the sensitive text with a similar, random value.
`STATIC_REPLACE`	Replace the sensitive text with a given value.
`CRYPTO_REPLACE`	Replace the sensitive text with its encrypted value.
`HASH_SHA256_REPLACE`	Replace the sensitive text with its SHA256 hash value.
`SHIFT`	Shift the date by a number of months, days, and/or years.
`SHIFTRANDOM`	Shift the data by a random number of months, days, and years.
`RELATIVE`	Replace the date by a words relative to the date.

Filter Strategy Options

The following filter strategy options are available for the RELATIVE filter strategy.

	Description	Default Value
`futureDates`	When `true`, future dates are replaced by relative words. When `false`, future dates are redacted.	`false`

The following filter strategy options are available for the SHIFT filter strategy.

Option	Description	Default Value
`shiftDays`	The number of days to shift the date. Can be a negative or positive integer. Defaults to `0` if not specified.	`0`
`shiftMinutes`	The number of minutes to shift the date. Can be a negative or positive integer. Defaults to `0` if not specified.	`0`
`shiftYears`	The number of years to shift the date. Can be a negative or positive integer. Defaults to `0` if not specified.	`0`

Conditions

Each filter strategy may have one condition. See Conditions for details.

Conditional	Description	Operators
`TOKEN`	Compares the value of the sensitive text.	`==`, `!=`
`TOKEN`	Compares the sensitive text to some category, e.g. `birthdate`.	`is`
`CONTEXT`	Compares the filtering context.	`==`, `!=`
`CONFIDENCE`	Compares the confidence in the sensitive text against a threshold value.	`<`, `<=`, `>`, `>=`, `==`, `!=`

Differentiating Between Dates and Birth Dates

In some cases it may be necessary to redact birth dates and dates differently. Using conditions it is possible to determine if an identified date is a birth date. The conditional token is birthdate will determine if the identified date (token) is a birth date by analyzing the content surrounding the date.

Example Policy to Redact Dates

The following policy redacts dates.

{
   "name": "dates-example",
   "identifiers": {
      "date": {
         "onlyValidDates": false,
         "dateFilterStrategies": [
            {
               "strategy": "REDACT",
               "redactionFormat": "{{{REDACTED-%t}}}"
            }
         ]
      }
   }
}

Example Policy to Shift Dates

The following policy to shift dates forward by 2 days and 4 months.

{
   "name": "dates-example",
   "identifiers": {
      "date": {
         "onlyValidDates": false,
         "dateFilterStrategies": [
            {
               "strategy": "SHIFT",
               "shiftDays": 2,
               "shiftMonths": 4,
               "shiftYears": 0
            }
         ]
      }
   }
}

Last modified: 17 November 2023