Like traditional mutual funds, ETF NAVs are also calculated once per day after the markets close.

FORBES: ETFs and the Uselessness of iNAV

Pew also found that 53 percent of Americans who use their phones to go online do so at least once per day.

CNN: Survey: U.S. mobile Web access growing fast

For example, 42% of female online gamers socialize with friends and family in person at least once per day versus 31% of females who do not play online games.

FORBES: Connect

In another recent cancer prevention study that found no excess heart risk in Celebrex users, patients only took Celebrex once per day, not twice as in the NCI study, potentially reducing any damaging effects to the heart from Cox-2 inhibition.

FORBES: More Pain For Pfizer

He missed the sailing and spent two weeks ashore without liberty, sleeping on the beach and eating once per day at a Baptist mission on the waterfront, until he was confident that Kinney was closer to Hong Kong than to Honolulu.

NEWYORKER: Share

The injectable medicine, for hospital-acquired infections, would be given once per week, compared with twice per day for mainstay vancomycin.

FORBES: Pfizer Plays A Guessing Game

Consequently, one in two respondents reported leaving the office on coffee or snack runs at least once a day, with some making as many as five trips per day.

FORBES: Lack of Snack Leads To Declined Productivity

Those animals' depressive symptoms, at least, went away once the hamsters returned to a schedule that included eight full hours of total darkness per day.

CNN: Unplug! Too much light at night may lead to depression

Mental health challenges were once taboo subjects in the workplace, but as Americans now spend roughly nine hours per day at work, silence is an increasingly costly strategy.

FORBES: Workplace Mental Health: It Pays To Be Proactive

Once production gets started, the field would pump out 1.5 million barrels of oil per day, to be shared amongst the investment group.

FORBES: Magazine Article