Children from deprived areas of Scotland are more likely to be absent from school than other pupils.
Children who receive free school dinners are more likely to truant
Latest attendance figures showed pupils registered for free school meals were away for an average of 10 days more than those who do not receive them.
Overall, school attendance rates in Scotland have risen to 93.3%, compared with 92.1% in 2005/2006.
The official figures also showed one in five pupils were taken out of classes during term-time to go on holiday.
New guidelines have been issued which will only allow term-time breaks in "exceptional circumstances".
Children's Minister Maureen Watt warned parents that it was "unacceptable" to take children on holiday when they should be in school.
The figures were revealed in annual attendance statistics published by the Scottish Government.
Across Scotland last year 656,000 pupil-days were lost to holidays - only a quarter of which were authorised.
The minister told BBC Radio Scotland: "Regardless of whether you are going to Florence, Florida or Fuengirola, it's not acceptable to take your children out of school."
Overall attendance rates in primary schools were 95.3%, falling to 90.6% for secondary schools.
Attendance levels were stable throughout the primary years, then fell off in the early years of secondary school with truancy peaking at S4.
Attendance levels then increase slightly in S5 and S6.
There was little difference between boys and girls but boys had "noticeably" better attendance rates from S4 to S6.
Within the overall absence rate of 6.7%, days lost through sickness accounted for 3.1%.
The second most common reason was "other authorised absence", accounting for 1.9% of days lost.
According to officials, this category should only apply to reasons like lack of transport, weddings, bereavements, or religious observances.
Holiday absence rates were highest in primary school and lowest in S4 to S6.
Isabel Hutton, of council umbrella group the Convention of Scottish Local Authorities (Cosla), said: "The statistics show that, overall, attendance is improving and this is to be welcomed.
"But it is still not good enough that it is the pupils who need the most support who are more likely to have higher than average absence."
Tory education spokeswoman Liz Smith said: "We can see from looking at the facts that truancy rates reach a peak in S4.
"This is yet further evidence that at this stage of education, large numbers of many pupils disengage with the current, predominantly academic, curriculum."