Export Day one backup file
1, Export from Dropbox
If you sync your Day One's data with Dropbox, you can export it as below:
2, Export from iCloud
You can use third party tools to export your iCloud's data.
We use iExplorer as an example. You can download iExplorer, find iCloud - > Day One - > Documents, drag Journal_dayone out. (iExplorer download address: http://www.macroplant.com/iexplorer/)
3, Export from Day One's Mac App
Open Day One's preference. Enter Backup - > Show Backups Folder in the Finder - > select a Backup file - > extract the files
Import to Grid Diary
After getting the data from Day One can begin to import it to Grid Diary, first connect the device to iTunes find Grid Diary, copy file into Grid Diary.