出境单次不能超过连续90天，5年不能超过180天。 是否是1年之内不能超过90天不清楚。
楼上回复你的说法是不正确的，T1E的settlement要求关于离境时间的具体规定如下：
The applicant has spent the specified continuous period lawfully in the UK,
with absences from the UK of no more than 180 days in any 12 calendar
months during that period.
因此是每年出境时间不能超过180天。
具体要求在requirements of indefinite leave to remain - paragraph 245DF 上可以看到。
不要道听途说，找律师行的话也找正规点的有实力的。
具体规则是按照楼上的明文，实际上五年累计也不要太多，总共超过180天就会开始有麻烦。
太谢谢了，不胜感激。:handshake 
麻烦能不能给个链接网址， 我再去具体看看。
找到了是这个，可以再具体帮我分析下吗？ 谢谢
245DF. Requirements for indefinite leave to remain
To qualify for indefinite leave to remain as a Tier 1 (Entrepreneur) Migrant, an applicant must meet the requirements listed below. If the applicant meets these requirements, indefinite leave to remain will be granted. If the applicant does not meet these requirements, the application will be refused.
Requirements:
(a) DELETED
(b) The applicant must not fall for refusal under the general grounds for refusal, and must not be an illegal entrant.
(c) The applicant must have a minimum of 75 points under paragraphs 35 to 53 of Appendix A.
(d) The applicant must have sufficient knowledge of the English language and sufficient knowledge about life in the United Kingdom, in accordance with paragraph 33BA, unless the applicant is under the age of 18 or aged 65 or over at the date the application is made.
(e) The applicant must not be in the UK in breach of immigration laws except that any period of overstaying for a period of 28 days or less will be disregarded.
没有找到具体离境时间啊，可以不可以再给个链接啊 ，谢谢了， 跪拜啊 ！！！！！！！！！！！！！
你又沒說你是Tier 1 的哪種。5年180天是Tier 1 (General). 每年180天是Tier 1 (Investment / Entrepreneur).
http://www.ukba.homeoffice.gov.uk/sitecontent/documents/policyandlaw/modernised/cross-cut/ilr-calculating-continuous/ilr-calculating-continuous.pdf?view=Binary
不客氣~
Paragraph 245DF里面有表格说明T1E转永居需要多少分，分别需要什么条件，里面就有说明出境时间的规定。
我的理解也是这样的