You can use the following date and time functions in your fields' display text or in the values of your skip or validation logic.
| Function | Description | Example |
|---|---|---|
| today() | Returns a string with today’s local date. | |
| now() | Returns the current date and time including timezone offset. | |
| format-date(date value, string format) | Returns the provided date value formatted as defined by the format argument using the following identifiers: %Y: 4-digit year, %y: 2-digit year, %m 0-padded month, %n numeric month, %b short text month (Jan, Feb, etc), %d 0-padded day of month, %e day of month, %a short text day (Sun, Mon, etc). | =format-date($mydate, "%a, %e %b %Y") returns a date that looks like Tue, 1 Jan 2019. |
| format-date-time(dateTime value, string format) | Returns the provided dateTime value formatted as defined by the format argument using the same identifiers as format-date (see above) plus the following: %H 0-padded hour (24-hr time), %h hour (24-hr time), %M 0-padded minute, %S 0-padded second, %3 0-padded millisecond ticks. | =format-date-time(now(), "%H:%M:%S") returns the current time in the format HH:MM:SS |
| date(* value) | Converts to a string in the current date format. | Dates stored as text would need to be converted to date format in order to use the date functions. |
| decimal-date-time(dateTime value) | Converts dateTime value to the number of days since January 1, 1970 UTC. | |
| decimal-time(time value) | Converts time value to a number representing a fractional day in the device’s timezone. For example, noon is 0.5 and 6pm is 0.75. |
Tip: if your calculation does not seem to work correctly, try adding white space around the operator, e.g. instead of "=($field_1+5)" use "=($field_1 + 5)"
Also see here for more functions and expressions you can use.
Example
The fieldworker must record the date of the interview. Validation must be added to ensure that no date in the future is accepted for this field.
- Click on the Validation tab of the field.
- Select the comparison type to be 'less than or equal to'.
- For the value to compare against, type '=' then select today().
