"daily obligation" is correct and can be used in written English.
You can use it to refer to a task or duty that needs to be done on a daily basis, such as "Brushing your teeth is a daily obligation."
We must therefore live as courageously and as honestly as we can while we can, never forgetting that we have a daily obligation to treat one another with decency, because we might never get another chance to do so.
Now that her first experience of putting on a play is over, Joan has taken to claiming that the daily obligation to spend time with other people is what most exhausted her about the life of the theatre.
"A lot of time has passed since then," said Robert J. Hollis, associate director of the Crispus Attucks center, who adds that the city is learning that human relations is a daily obligation and labor.
Citizen Service is about the daily obligation every citizen has to contribute to the healthy operation of self-governance -- and to help ensure the best from those we elect to represent our interests.
The money the company is generating is sufficient to meet its daily obligations, this person said.
Banks have long been required to deposit reserves at the central bank to ensure they can meet their daily obligations.
Kerry has vivid memories of the daily obligations of running a D.A.'s office, some of them bizarre.
Over time empty places in our lives get filled in with daily obligations and the gentle sifting of time.
Gates, in order to concentrate on his philanthropic interests, withdrew from daily obligations at Microsoft in 2008, making Ballmer even more prominent as the public face of Microsoft.
But in the last two months, Mr. Giuliani has been distracted by the daily obligations and crises common to the mayor of the largest city in America.
The observance of the daily obligations, including the care of bodily purity and professional duties, leads to earthly reward and helps to preserve the state of sanctity required to enter into contact with the divine.
