First document is Applications from overstayers (non family routes)
The routes it covers are:
all work and study, including the points-based system
visitors
long residency
UK ancestry, and
most discharged Her Majesty’s (HM) forces.
it say same thing
Any applicant who is applying for leave to remain must not have remained in the UK for
longer than 28 calendar days after the expiry of their original grant of leave, on the date of
their application. Remaining in the UK after leave has expired is commonly known as
overstaying
The 28 day period of overstaying is calculated from the latest of:
the last day of their latest grant of leave to enter or remain, or
the end of any extension of their leave under sections 3C or 3D of the Immigration Act
1971.
Calculating the date the period of overstaying begins
You must calculate the date on which the period of overstaying begins based on the last day
of the migrant’s latest grant of leave to enter or remain, or when leave under section 3C or
3D ended. You must take into account any variation on the duration of leave, such as a
curtailment decision.
The first day of the 28 day period begins on the first day after the day the migrant’s leave
has expired. This is unless the migrant has submitted an in-time application which has not
been decided before their leave expires.
If the migrant did make an in-time application and the application is subsequently refused,
the migrant’s leave will have been extended by virtue of section 3C of the Immigration Act
1971
