great idea!
month for month... each planet each own month =ddd

das Septemberbild ist richtig klasse

I think is a great idea. If you have a concept you can go ahead and make the theme. If not you can show them with a message as to why you think they should be in that month. Hope this helps. ^^

They don't always have to fit the month. Especially considering the fact that northern and southern hemispheres have different experiences throughout the year (yep, believe it or not - for half the globe, January is hot ) But a "theme" is good. All calendars have a theme, that way it ensures those interested in one pic would likely like the rest Whose gonna buy a calendar where one month is a drawing of a dog and the next is a photo of a building etc

"The images used should have something in common and should fit to the month" Also, das du wenn du Landschaften benutzt, auch nur landschaften verwendest und nicht plötzlich auf.. tiere umspringst Sonst ne coole idee!