Balinese society has ways to greet each other, their coverage of his hand across his chest and say:
“I hope all good comes from all directions”
Om Swastyastu understanding which in Sanskrit is combined from three words: Om, Swasti and astu. The term of this Om is a sacred term as a designation or call on God Almighty in Hinduism. Saying Om that means a call for prayer to worship and praise God. In the Bhagavad Gita says Om is expressed as a symbol to pray to God. Therefore say Om wholeheartedly mean that we pray to God, which means Oh God.
After saying Om, Swasti followed by a word. In Sanskrit word Swasti meaning safe, happy and prosperous. And astu means hopefully. Thus Om Swastyastu means: Oh God, I hope all good (safe, happy and prosperous) comes from all directions.
This is a form of respect for fellow human beings, by saying that hope we meet in the good feelings and thoughts in order to establish a harmonious relationship.
If the coverage of the hand over the crown then it shows reverence to God, if the coverage of the hand between the forehead then it shows reverence to the ancestors, if the coverage of the hand in front of the chest then it shows respect to fellow human beings, if coverage under the hand and looked down then it shows respect to the lower creatures than human beings like animals and other spirits (bhuta kala)
Regards Om Swastyastu did not choose the time. He can be pronounced morning, afternoon, evening and night. Hopefully Om Swastyastu auspicious greetings to grab the gift God gave mankind salvation.