know the time of day

not know the time of day

To be completely unintelligent, daft, or not alert. We paid for her to attend the best university in the state, but three years in, she still doesn't know the time of day. How can you expect me to respect my boss when he doesn't even know the time of day?
See also: know, not, of, time
Farlex Dictionary of Idioms.

know the time of day

be well informed about something.
See also: know, of, time
Farlex Partner Idioms Dictionary
See also:
  • not know the time of day
  • slow study
  • (as) daft as a brush
  • daft as a brush
  • daft
  • I wasn't born yesterday
  • poophead
  • not the full quid
  • make (one) feel small
References in periodicals archive
Amateur historian Dr Naylor Firth, of Itton, Monmouthshire, told the BBC: "We do not know the time of day he died.
We relied on it to know the time of day and it was our school train.
Both rider and trainer know the time of day when it comes to this heat as each has two victories to their credit in the last 10 years.
Or is it more to do with a home secretary who doesn''t know the time of day, a defence ministry in chaos, the incompetent handling of the tanker drivers'' dispute, failed child poverty reduction targets or a host of other doomed promises?
Paul Nicholls is not committing Hinterland to the Triumph yet, and juvenile hurdlers are not exactly his stock in trade, but he has had enough good ones through his hands to know the time of day and so we ought to take notice when he describes him as "the best juvenile we've ever had at this stage of the season, without a doubt".
IF you want to know the time of day don't bother asking Sir Michael Stoute.
But I do need to know the time of day during a normal working week.
The 12-year-old will be unfazed at tackling this longer trip from a yard who certainly know the time of day.
Coral Spokesman Simon Clare said: "Ferdy Murphy has an exceptional record in the Scottish National and the money for Noir Et Vert came from punters who know the time of day.
The great thing about the Kirk yard is that people are not yet switched on to the fact that they know the time of day.
If, on the other hand, you want to know the time of day, you ask a bookmaker.
The four-year-old filly won her final two starts in handicaps last season and landed a Group 3 at Lingfield on her seasonal debut this month, when well backed in the market despite having plenty to find on the book with the French-trained Reggane, suggesting connections certainly know the time of day.
Illicit Spirit comes here from a choice of three engagements during the week and it's highly likely connections know the time of day concerning his real talent against a starting handicap mark of 104.
According to his trainer Coat Of Honour needs to go right-handed and, as all his wins have been clockwise, it's a slight worry that he is going the other way round here, although Johnson does know the time of day.
She sits in bed with the curtains closed and does not even appear to know the time of day. One lunchtime she was so disorientated that she believed it was breakfast.