Watchtower NWT
Genesis 2:1-3) Thus the heavens and the earth and everything in them were completed.  And by the seventh day, God had completed the work that he had been doing, and he began to rest on the seventh day from all his work that he had been doing.  And God went on to bless the seventh day and to declare it sacred, for on it God has been resting from all the work that he has created, all that he purposed to make.

A representative of most other translations:

Genesis 2:1-3 New International Version (NIV)

2 Thus the heavens and the earth were completed in all their vast array.

² By the seventh day God had finished the work he had been doing; so on the seventh day he rested from all his work. ³ Then God blessed the seventh day and made it holy, because on it he rested from all the work of creating that he had done.

Notice some differences (highlighted above).

The NWT implies that God began to rest on the 7th day and at some stage in the then future after he began resting he made the 7th day holy.

Most translations imply that God specifically rested on the 7th day with no mention of resting on subsequence days. The consequence of God resting on the seventh day after labouring for six says is that he made the seventh day a holy day of rest.

Just one example of Watchtower rewriting scripture to align with its doctrine and beliefs.