Month names are easier to remember than the days of the week because they’re so similar to English. Month names aren’t capitalized, unless another capitalization rule overrides it (such as when they’re at the beginning of a sentence). This post is more useful in conjunction with the posts about days of the week, number post one, and number post two.

Note: All z’s in Icelandic are now spelled with an s instead, so “Marz” (March) is now “Mars”.

These photos are from a 1935 Icelandic pocket almanac, you can see the abbreviations for the days of the week on the leftmost column. You might think an almanac is just for crop, tide, and moon information, but in Iceland it’s often much more. An Icelandic one may include things like a calendar with holidays, a planner, maps, road-sign meanings, and various conversion information.

Abbreviations:
jan.
feb., febr.
mar., mars.
ap., apr.
maí (none)
jún.
júl.
ág., ágú.
sep., sept.
okt.
nóv.
des.

I think this was taken at the National Registry Office in Reykjavik.

In Iceland you list the date as “day, month, year”, and they use periods instead of slashes to separate things. So 2.3.2012 would be March second, 2012. People almost never spell out numbers when writing. You also don’t put a comma after the month like in English, so it would be “2. mars 2012”.

Hvaða dagur er í dag? – What (which) day is today?
Hvaða mánaðardagur er í dag? – What day of the month is today? (More literally, “which monthday is to-day”?)
Hvenær er jóladagur? – When is Christmas Day?
Hvenær fæddist þú? – When were you born?
Hvenær ertu fæddur? – When were you birthed? (“when areyou birthed”?)
Hvenær áttu afmæli? – When is your birthday? (“when haveyou a birthday?”
Í hvaða mánuði áttu afmæli? – In what month is your birthday? (“in which month ownyou birthday?)
Ég á afmæli í… – My birthday’s in… (“I have a birthday in…”)
Ég á afmæli síðasta daginn í… – My birthday’s on the last day of… (“I have a birthday last daythe in…)
Ég á afmæli daginn eftir… – My birthday’s the day after…

When saying days of the month aloud or spelling them out, you’d use ordinal form as described here. Notice also that if you say the date, you completely skip out on the “on the” and “of” part of “My birthday’s on the twenty-first of September”.
Ég á afmæli tuttugasta og fyrsta september. (The p in “september” is pronounced like f!)
More literally: “I own a birthday twentieth and first September”.

If you have a chance to listen to the Icelandic children’s radio station, they often play a song with the days of the week and the names of the months. It’s really good for hearing a clear pronunciation of the words but I haven’t yet found it online, so if you find it please comment here!