It's not good to put the clock across the door. The clock should not be placed on any door. Generally, it should be placed in an open place, such as outside the window. Because the clock also has the function of ward off evil spirits, if there are evil spirits outside the window, you can also aim the clock at the side of evil spirits and resolve them under the condition of placing items.
Where the clock should not be placed
The clock should not be hung above the sofa. Otherwise, people who often sit here are prone to anxiety.
Putting or hanging clocks in the bedroom is basically the same as in the living room, but clocks can't be hung at the end of the bed.
The clock should not be placed or hung on the white tiger side of the house (that is, in the west), because the white tiger side is the so-called fierce side of traditional geomantic omen, so it is not appropriate to place the clock on the right side of the house. But it can be placed or hung in the northwest of the house, and the color of the clock should be mainly white and gold, and the shape should be round, because this position belongs to gold.