Validate RFC3339 date-time using php

Question

Any recommendations how to validate that a date-time is valid RFC3339?  I know I can convert it to unix time and then format it as valid RFC3339, but don't wish to do so and instead enforce that the correct format is provided.  http://mattallan.org/posts/rfc3339-date-time-validation/ suggests using regex, will only do as a last resort.  Thanks

Answer 1

DateTime has a predefined DaTeTime::RFC3339 format constant. Since createFromFormat returns false if it can't parse the date according to the provided format, you can use that check as your validator:

validRFC3339Date("2018-01-29T20:36:01Z");
validRFC3339Date("2018-01-29T20:36:01+00:00");

validRFC3339Date("2018-01-22 20:36");
validRFC3339Date("2018-09-28T16:00:05.000Z");

function validRFC3339Date($date) {
    if (DateTime::createFromFormat(DateTime::RFC3339, $date) === FALSE) {
        echo "$date: Invalid RFC3339\n";
    } else {
        echo "$date: Valid RFC3339\n";
    }
}