Contradiction with Matthew 24:36
Revelation 6:1 suggests John's knowledge about the events as they begin, while Matthew 24:36 states that no one knows the day or hour.
Matthew 24:36: But of that day and hour knoweth no [man], no, not the angels of heaven, but my Father only.
Contradiction with 1 Thessalonians 5:2
Revelation 6:1 reveals events at the opening of the seal, but 1 Thessalonians 5:2 depicts the Lord's coming as a thief in the night, implying unexpectedness.
1 Thessalonians 5:2: For yourselves know perfectly that the day of the Lord so cometh as a thief in the night.
Contradiction with Mark 13:32
Revelation 6:1 shows foreknowledge of the end times, whereas Mark 13:32 emphasizes the unknown timing, even to angels and the Son.
Mark 13:32: But of that day and [that] hour knoweth no man, no, not the angels which are in heaven, neither the Son, but the Father.
Contradiction with Acts 1:7
Revelation 6:1 involves knowledge of future events, while Acts 1:7 indicates that such knowledge is not for humans to know.
Acts 1:7: And he said unto them, It is not for you to know the times or the seasons, which the Father hath put in his own power.