Batch Renaming Files using Automator (Mac OSX)

Cmd+spacebar to search for Automator

Steps:

1. On left panel, select Files & Folders
2. Drag 'Get Selected Finder Items' to the right panel
3. Drag 'Rename Finder Items' to the right panel
4. Change the default 'Add date or time' to 'Replace text'
5. My initial files start with 'IMG_' (refer Fig. 2). Change yours accordingly
6. Replace all the files with 'Date-Occasion' (make sure all the related files are selected, refer Fig.2, and the folder you are working is current active windows)
7. Hit 'Run'

Fig. 1 Automator

Fig. 2 Select related files for batch renaming