あけましておめでとうございます

Meanings

polite (teineigo)usually written using kana alone

Polite New Year's greeting used from January 1st onward. The phrase literally means 'congratulations on the opening (of the new year)'. It is the standard formal greeting for the new year period.

明あけましておめでとうございます。今年ことしもよろしくお願ねがいします。
Happy New Year. I look forward to your continued friendship this year.
新しん年ねんのご挨あい拶さつ：明あけましておめでとうございます。
New Year's greeting: Happy New Year.

Kanji

明bright, light
御honorable, manipulate, govern
座squat, seat, cushion
目eye, class, look
出exit, leave, go out
度degrees, occurrence, time

Related words

謹きん賀が新しん年ねん
明けましておめでとうございます is spoken (or casually written) year-round-appropriate greeting, while 謹賀新年 is a stiff, formal phrase used almost exclusively on New Year's cards.
あけおめ
明けましておめでとうございます is the full polite greeting, while あけおめ is its casual, shortened slang form used only with close friends.

Written forms

明あけましておめでとうございます
Standard kanji-kana mixed spelling; the most common written form.
明あけましておめでとう御ご座ざいます
rarely-used kanji form
Rare kanji form using 御座います for ございます; mostly seen in formal or traditional contexts.
明あけまして御お目め出で度とう御ご座ざいます
rarely-used kanji form
Very rare full-kanji form; archaic and decorative.

Etymology

From 明ける (akeru, 'to dawn, to begin') in its continuative form 明けまして (akemashite) + おめでとう (omedetou, 'congratulations') + ございます (gozaimasu, polite copula). The phrase literally means 'congratulations on the beginning (of the new year)'.