Although all 24 hour periods might be yoms, all yoms are not necessarily 24 hour periods. Anyone who has ever been a party to a custody dispute, rental agreement or labor negotiation knows that you can't even arrive at a plain meaning of the word day in English, let alone ancient Hebrew. When referring to the word day do you mean:
1) a legal day as defined as the period between midnight and midnight
2)An astronomical day as defined the period between noon and noon
3) The day light hours only
4)the period of rotation of a planet or a moon on its axis
5) a specified day or date (the day of the hearing)
6) a specified time or period : age (in grandfather's day)
7) the conflict or contention of the day (fought hard and won the day)
8) the time established by usage or law for work, school, or business
9) an unspecified past or future time (one day)
10) one'd life time (to spend one's days)
This one is of particular significance with respect to the passage you cited. In Creation a yom is the light and the dark period, in general ancient Hebrew language a yom is the day light hours only. Surely you cannot imply that God wishes that we toil for six full days (144 consecutive hours) uninterrupted as He did. If you are referring to man only having to toil the daylight hours then even the duration of this varies with the seasons as Israel is 32 degrees north of the equator. The hours of daylight vary from 10:14 in December to 14:04 in June.
when taken in context the meaning is clear. You refuse to see it in context.