If you wish to apply for ILR you must have had no more than 180 days’ absence from the UK during any rolling 12 month period during the applicable two, three or five year qualifying period. You are required to list your absences when applying for ILR and so you should retain a record of these.
Dependants of Investor visa holders who were granted their initial or extended visa on or after 11 January 2018 must also meet the above absence requirements for any period of leave granted after this date.