In 0.115, templates in the Template integration are evaluated more efficiently. However, the new technique has deprecated the use of the entity_id option.
That means the entity_id option in your Template Sensor is now ignored (so sensor.time is not being included). Your template contains no entities (so no listeners can be assigned) therefore it is evaluated at startup and never again (until the next restart).
The reason why that works is because sensor.time has been included in the template (it also works with all versions of Home Assistant prior to 0.115). Here’s another way to include sensor.time:
Actually, that was my mistake (and I’ve corrected the example). Call it a brain-fart but I used the wrong character to indicate line-continuation.
The greater-than symbol is still used to indicate that the template starts on the following line. The reason I used it is for consistency; both examples employ it and the second one becomes messier if one attempts to represent it all on one line.
If the template consists of one (short) line then, yes, you can dispense with the > and simply put the template on the same line as value_template (remembering to delimit the template with quotes).