When performing Smith Machine squats you virtually have an infinite number of options as far as foot placement goes, which allows you to target your quads and glutes in different ways and to different degrees without any regard for maintaining your balance.
When entering time, the decimal point is used to represent a percentage of an hour. For example, 2.25 = 2 hours 15 minutes. 2.5 = 2 hours 30 minutes. 1.7 = 1 hour 42 minutes. If you want to designate minutes when you enter time, use a colon. 2:15 = 2 hours 15 minutes.
The 24-hour clock notation avoids these ambiguities by using 00:00 for midnight at the start of the day and 12:00 for noon. From 23:59:59 the time shifts (one second later) to 00:00:00, the beginning of the next day. In 24-hour notation 24:00 can be used to refer to midnight at the end of a day.