How to determine the location of a card in a deck using a clock

The description of the focus is as follows. The spectator chooses one of six cards, gives cards to you, you stack them in a deck. Then you look at the clock, for example, they show 12 hours and 17 minutes, add up 12 and 17, get 29. Take the deck and start counting down the cards until the twenty-ninth card, and the twenty-ninth card turns out to be the map the spectator chose.
The secret of the focus is that you need to make sure that the card is in advance in the twenty-ninth place and guess the execution of the focus in time, for example, at 12 hours and 16 minutes. In order for the card to be on the 29th place, it is necessary to do the following manipulations. Invite the viewer to pull out 6 cards, select one of them and set it aside. Then you divide the remaining deck into two equal parts and put these piles on the table in a closed form. Then take the selected card by the spectator and put it on the first pile, the remaining 5 cards put on the second pile. After that, put the second stack on the first stack. As a result, the chosen card turns out to be the twenty-ninth. To accurately predict the performance of time by the hour, you need to practice and determine in advance how long it takes for all manipulations and already knowing the time, you can perform the trick.