private boolean isValidFormat(String value, DateTimeFormatter format) {
        try {
            format.parse(value);
            return true;
        } catch (DateTimeParseException e) {
            return false;
        }
    }
Validates that timestamp shapes contain values that are compatible with their
timestampFormat traits or contain values that are numbers or an RFC 3339
date-time production.
smithy-model/src/main/java/software/amazon/smithy/model/validation/node/TimestampFormatPlugin.java