aCalendar

The app lets you view the calendar in multiple ways, by day, week, month or year. You can mark contact birthdays in the calendar and view holidays in multiple countries. It integrates with your Google Calendar and automatically retrieves entries from there.  
 
aCalendar comes with multiple customization tools, including the option to change the theme, adjust start view, font size and color for the current day. You can view moon phases, scan QR and NFC barcodes to share events or use home screen widgets. It also lets you create business events and invite attendees, link contacts or share them on social networks. Moreover, the app lets you manage Google Tasks entries or specify the location of an event.