journal Jan 2011
今天我应该工作，上课没有。 我想写中国经济的文章，所以今天要研究中国生活。 而且最近我跟孩子们玩儿，周一我女儿去加拿大坐飞机，周二我儿子要去北京。
trevorbJanuary 03, 2011, 06:25 PM
Is it more usual to use 周一 rather than 星期一? or is this entirely up to personal preference.
In modern vernacular
女儿 是 三十一岁了，儿子是二十七岁了。
If you are wondering about the use of 了- I believe that it is probably superfluous these days. As well as confusing. My teacher taught me that you should say the age that your child achieves in the current (lunar) year, and if they have already had their birthday you add 了. That may hark back to the days when everyone became a year older at Chinese New Year.
Secondly there is an issue about whether you count from 0 or 1. My current crop of Chinese students have never heard of that practice, or the one about using 了 .. things are changing in China. Applying the traditional rules for the 了 (in this case) 女儿 是 三十一岁了，儿子是二十七岁了。 Exactly the same, because they have both had their birthdays already.
Hopefully one of the ChinesePod teachers might have a comment.
Ah I've heard about the zero or one thing 实岁（周岁）born at 0 years old vs 虚岁 xu1sui4 born at 1 year old already!
remember that from 老外中文 （http://laowaichinese.net/how-old-are-you-on-mars.htm）
Apparently I could say 今天我大儿子十岁十九岁了。。