At a press conference in Brussels, the bureau chief of German news broadcaster ZDF sang her "Happy birthday, liebe Bundeskanzlerin (dear Chancellor)," and a 1,000-person banquet will be conducted in her honor Thursday by her Christian Democrat Party in Berlin.
The banquet will be hosted by historian Jurgen Osterhammel, prominent for his essays on 19th-century empire-building, and analysts read into it a sign that Merkel has tired of domestic politics and seeks a bigger forum in international affairs.
She would be the first sitting Chancellor to resign, if it happens.
"She seems not to be putting much heart into the issues on her to-do list", journalist Nikolaus Blome wrote in Der Spiegel magazine.
Blome speculates Merkel may seek the European Union council presidency or the position of United Nations Secretary-General, a position that will be available in 2017, immediately before the next general election in Germany.
Merkel was born in East Germany, and had that government not collapsed and been absorbed into the Federal Republic of Germany, Merkel would be collecting her pension today, Left Party politician Stefan Liebich writes in a mostly-favorable magazine article about her this week.
She is regarded as Europe's most powerful politician, and has a 77 percent approval rating in Germany.