I don't really know about America (why am I even making this book wut), but in the UK the school year starts in the first week of September in some and others schools are often a little later in starting and finishing and have 7 weeks on holiday.
The school year ends in July- a lot later than quite a few other countries and the average student between ages 5-18 gets 6 weeks on holiday.
G R O U P I N G
It goes like this:
Say you were born on or after the 1st of September 2015 (01/09/2015); you would be in the same year group as somebody born on the 31st August 2016 (31/08/2016) and all the other ages between that.
If you were born on and between 1st September to 31st August in the following year (as in the August next year), you are one year group.
T E R M S , S E M E S T E R S , H O L I D A Y S
Please correct me if I am wrong.
Terms are the same as semesters- they are just called different things in different places.
There are 3 terms in the UK Autumn, Spring and Summer. The time frames can vary but generally the months are:
Autumn= September-December
Spring= January- March
Summer= April-July
Each term is broken into 2 with a holiday inbetween so in total we have 6 holidays in the UK. Again the amount of holiday time varies as some schools may give more than others, but here are the holidays with the general timeframes:
Autumn half term = 1 week; during last week of October (25/10/2014-02/08/2014)
Winter holidays= 2 weeks; second to last week of december to second to last week of January
Spring half term= 1 week; second to last week of February
Easter holidays= 2 weeks; last week of March to second week of April
Summer half term= 1 week; last week of May
Summer holidays= 6/7 weeks; second to last week of July to first week of December
so in total we have around 13-14 weeks of holiday which is 2 months excluding bank holidays, public holidays and INSET/INSED days!
INSET/INSED days are usually staff training days and the staff have to come in but the students don't!