This code converts a 32-bit int value to a 64-bit long value, and then passes that value for a method parameter that requires an absolute time value. An absolute time value is the number of milliseconds since the standard base time known as "the epoch", namely January 1, 1970, 00:00:00 GMT. For example, the following method, intended to convert seconds since the epoc into a Date, is badly broken:

Date getDate(int seconds) { return new Date(seconds * 1000); }

The multiplication is done using 32-bit arithmetic, and then converted to a 64-bit value. When a 32-bit value is converted to 64-bits and used to express an absolute time value, only dates in December 1969 and January 1970 can be represented.

Correct implementations for the above method are:

// Fails for dates after 2037
Date getDate(int seconds) { return new Date(seconds * 1000L); }

// better, works for all dates
Date getDate(long seconds) { return new Date(seconds * 1000); }