I can propose this
These are two questions, the date/timepicker and a multiple question with only one subquestion
Merged by a little bit of css.
Add this to your "custom.css"
Code:
.disable-irrelevant.ls-irrelevant.ls-hidden{display:block;}
.disable-irrelevant.ls-irrelevant .form-control{background-color: #eee;cursor: not-allowed;}
.no-question{border-top:0;}
.no-question .question-title-container{display:none;}
.no-question .question-valid-container{display:none;}
.no-question .answer-container {
padding-top: 0em;
padding-bottom: 0.5em;
}
.no-bottom{border-bottom:0;margin-bottom:0;}
.no-bottom .answer-container { padding-bottom: 0em;}
Add
the css class "no-question" to the multiple question,
the css classes "disable-irrelevant no-bottom" to the time picker question
the relevance equation "is_empty(QMulti_SQ001.NAOK)" to the time picker question.
Joffm
By the way: It would be much easier, if you used a question of type short text to enter the time; here you may use the plugin "checkBoxForText" to add the "no answer" option