Yes, that is true in situations where you travel to USA for work on Morning (say 8:00 am) and return back in the evening (say 6:00 pm). In that case, you would still sleep in Canada after working in USA. This is how I have been counting my days till now. Others/Experts could also chime in.
- The calculation of physical presence cannot go beyond the five-year period before the date of application.
- Each day of physical presence in Canada as a permanent resident counts as one day.
- Each day of physical presence in Canada as an authorized temporary resident or protected person before becoming a permanent resident, counts as one half day, with a maximum of 365 days credit towards physical presence.
- February 29 (leap day) is counted in either presence or absence.
- Absences will be calculated only for days where an applicant spent no time at all in Canada. Dates where an applicant left Canada, or returned to Canada will not be counted as an absence since the applicant was physically present in Canada for a portion of both days.
- Time spent serving a sentence and absences must be subtracted from the total number of days of physical presence during the five-year period.
https://www.canada.ca/en/immigration-refugees-citizenship/corporate/publications-manuals/operational-bulletins-manuals/canadian-citizenship/grant/residence/calculate-physical-presence.html#s04