Platform, device version and operating system:
XBOX/PS4
What you were expecting to happen, and what actually happened:
New Monthly Reward calendar for January expected in calendars. The calendar is not there. A related post was made in PC/Mobile gameplay chat, where users claim they still have the calendar. No patch notes indicate a loss of this reward calendar.
How often does this happen? When did it begin happening?
Ongoing
Steps to make it happen again
Start game
Thank you. I edited my post to show as a Ps4/Xbox (lack of a) feature.
It has vanished on PS4 too.
Updated title and report to include both consoles.
Thanks for bringing this to our attention, we’re looking into it now.
Will you be able to retro apply the previous dates rewards on PS4/Xbox to make sure we can get all the monthly calendar rewards once it is resolved?
Also do you need a screenshot if so I can provide one.
tldr; 
We better still get that chaos orb.
gotta get dat monthly orb of growth
Hey, this will be fixed at daily reset today.
global mail will be sent on PS4 and Xbox with the first 3 day’s rewards.
The January Calendar will start on day 1 with the day 4 rewards on Day 1.
That means the calendar will be 25 days long with the Orb on day 25 so you don’t miss anything.
I’ve written a known issue article for the help center about this which will stay up all month. I’ll publish it once the fix is live.
Thank you for the quick turn around time on this and for sending the missing rewards @Kafka you guys rock!
Mail sent and calendar active again 
Dear devs. We at switch have this same problem. For going on 2 months. I don’t really give much for most of the rewards, but diamonds and orbs being missed is making my irritation skyrocket.