涵涵君的小站中文
中国签证上的“有效期至”和“停留天数”是两个不同的概念。搞清楚两者的关系，才知道自己最晚哪一天必须离境。
- 有效期：签证自签发之日生效，在“有效期至”（Expiry Date）所示日期（北京时间）当日24:00后失效。
- 停留天数：指每次入境后可停留的最长天数，从入境次日起计算，入境当天不计入。
- 最关键的一条：如果仍在签证允许的停留期内，即使签证本身已经过期，也可以合法停留，但不得超期。这正是很多人误判的地方——签证的失效日不等于必须离境的日期，必须离境的日期由停留天数决定。
- 入境次数（Entries）：指在签证有效期内允许入境的次数，一般为一次、两次或多次。一次或两次签证在入境次数用完后即失效；如果签证仍在有效期内但入境次数已经用尽，需要重新申请。
- 信息不可更改：签证一经签发，有效期、停留天数和入境次数均不得更改；确需变更，只能重新提交申请并缴费。
延期怎么办：停留天数不够用的，须在停留天数届满之前向公安机关出入境管理机构申请延期，是否批准由公安机关决定。按出境入境管理法第三十六条，不予延长停留期限的决定为最终决定，所以行程安排不要把希望全部押在延期上。
另一条容易忽略的规则：持 D、Z、X1、Q1、S1、J1 签证入境的人员，应当在入境30日内办理居留许可，逾期未办属于非法滞留。这类签证的“停留天数”只是入境后办理居留许可的过渡期，不能当成可以长期停留的期限。
核对方法：拿到签证后逐项核对姓名、护照号、签证种类、入境次数、有效期至、停留天数六项。任何一项与护照信息不一致，都应在出发前联系签发机关或签证申请服务中心处理，不要带着有疑问的签证登机。
以上为要点摘录，具体以官方发布为准。
English
Visa Expired but Stay Still Valid? Reading China Visa Dates
The expiry date and the duration of each stay on a Chinese visa are two different things. Understanding how they relate tells you the last day you may legally remain in China.
- Validity: a visa takes effect on the date of issue and expires after 24:00 Beijing time on the date shown as the Expiry Date.
- Duration of each stay: the maximum number of days you may remain after each entry, counted from the day after entry. The arrival day does not count.
- The key point: if you are still within the permitted duration of stay, you may remain legally even after the visa itself has expired, but you must not overstay. This is where many people misjudge their situation: the visa expiry date is not the date you must leave; the duration of stay decides that.
- Entries: the number of times you may enter during the visa's validity, usually single, double or multiple. A single or double entry visa becomes invalid once its entries are used up. If the visa is still valid but the entries are exhausted, you must apply again.
- No changes after issue: validity, duration of stay and number of entries cannot be altered once the visa is issued. If you need different terms, you must submit a new application and pay the fee again.
Extensions: if the permitted stay is not long enough, apply to the exit-entry administration for an extension before it ends; approval is at the authority's discretion. Under Article 36 of the Exit and Entry Administration Law, a decision not to extend is final, so do not build your plans on the assumption that an extension will be granted.
A rule that is often missed: holders of D, Z, X1, Q1, S1 and J1 visas must apply for a residence permit within 30 days of entry; failing to do so counts as illegal residence. For these visa types the duration of stay is only a bridge period for obtaining the residence permit, not a long-stay allowance.
How to check: after collecting your visa, verify six items one by one — name, passport number, visa type, number of entries, expiry date and duration of each stay. If any item does not match your passport, contact the issuing authority or the visa application service centre before departure rather than boarding with a questionable visa.
The above is a summary of key points only. Please refer to the official announcement for the authoritative version.
来源：原文链接
