Visa processing in the UK: Can the entry time be advanced?

The entry time cannot be earlier than the entry time stipulated in the visa.

A "visa" is a document that a foreigner who travels is approved by the destination country to enter the country, which states the time limit for his entry and stay. The allowed stay time depends on the purpose of the visitor's visit, from one day (such as transit) to permanent (such as immigration). Some visas are only allowed to be used once, such as transit and one-time travel. It is invalid if it is stamped with the entry and exit stamp. Others allow multiple uses, such as business, study, immigration (and many round-trip trips implemented in some countries recently) and so on. Any visa must indicate the time limit allowed to stay after entry. In other words, "time limit" is an important part of the visa and indispensable.

There are two ways to define "time limit": one is defined by the specific date of entry and expiration of the visa (such as "entry date: March 5, 2000" and "exit date: June 4, 2000"), and the other is defined by the date of issuance of the visa plus the validity period (such as "issuance date: March 5, 2000" and "validity period: 3 months"). The former method is easy to manage and count, and is adopted by most countries. According to this visa, you can't enter the country before the entry time stipulated in the visa. If you need to enter the country in advance, you should make it clear when you apply for a visa. If you are rejected, you should arrange your trip according to the time allowed by the visa, and you can't force yourself to try to enter the country with luck.