The "day" given in the data refers to the rotation period, the sidereal day. The difference between a sidereal day and a solar day depends on the rate of rotation.

Mercury: 58.646d (R)

Venus: 243.019d *Venus has a significant difference between its sidereal day and solar day (116.75d). This is mainly due to the fact that its rotation period is even shorter than its spin period

Mars: 24.623h

Jupiter: 9.842h

Saturn: 10.233h

Uranus: 17.240h (R) *Data based on magnetic field

Neptune: 16.110h *Data based on magnetic field

Pluto: 6.387d (R)

*R means retrograde.