core/src/main/java/org/sakaiproject/nakamura/api/lite/authorizable/User.java
public void setLoginEnabled(long from, long to, boolean day, TimeZone timeZone) {
        String enabledSetting = EnabledPeriod.getEnableValue(from, to, day, timeZone);
        if (enabledSetting == null) {
            removeProperty(LOGIN_ENABLED_PERIOD_FIELD);
        } else {
            setProperty(LOGIN_ENABLED_PERIOD_FIELD, enabledSetting);
        }
    }
public void setLoginEnabled(long from, long to, boolean day, TimeZone timeZone) {
        String enabledSetting = EnabledPeriod.getEnableValue(from, to, day, timeZone);
        if (enabledSetting == null) {
            removeProperty(LOGIN_ENABLED_PERIOD_FIELD);
        } else {
            setProperty(LOGIN_ENABLED_PERIOD_FIELD, enabledSetting);
        }
    }
Sets the login enabled time

@param from
UTC ms time after which user login is enabled. < 0 means no
start time.
@param to
UTC ms time before which the user login is enabled, < 0 means
no end time.
@param day
true if the time represents a day rather than a time
@param timeZone
the timezone which both these times should be interpreted in
(relevant for a day setting).
@since 1.4