British law, especially as regards immigration and nationality, is very specific in terms of the requirements for both citizenship and immigration and is not nearly as forgiving as EU law.
Absence from the UK means being physically outside the UK (defined as including the Channel Islands and the Isle of Man). The day of arrival and departure are counted as being physically present in the UK. Only whole days spent outside the UK count as absence from the UK.
The purpose of being outside the UK, whether for work or for holiday, is immaterial. There is some discretion to waive the absence requirement, as mentioned by
@alterhase58 above, but even as regards exercising discretion, there are very specific requirements to be met. See "Absences during the qualifying period" on Page 16 of the
Nationality Guidance on Naturalisation as a British citizen at discretion.
Be aware that there is also a requirement for you to have been physically present in the UK at the start of the five year period immediately preceding the date of application for British citizenship (so, if you were to apply on 4th February 2020, you'd have to prove that you were physically in the country on 5th February 2015). The Home Office has no discretion to disregard that requirement.
Keep in mind that a naturalisation application also has a "future intentions" requirement (that you intent to reside in the UK). There have been two instances of successful applicants having their naturalisation
called into question because the applicant applied for their first passport from abroad, after their successful naturalisation in the UK.
So I would tread very carefully of spending a lot of time abroad in the near future if you plan to naturalise as a British citizen.
I am not a lawyer or immigration advisor. My statements/comments do not constitute legal advice. E&OE. Please do not PM me for advice.