In other words, all the records in the fact table should represent measurements take at a daily level, a weekly level, or a monthly level, for instance. Your proposal has time dimension records of varying grain and it appears that they overlap. In a uniform grain fact table you can use the associated time dimension to constrain in a simple way on many different spans of time. A time dimension table with entries for every discrete day is very flexible because in this table you can simultaneously represent all the useful time groupings you can think of. These are smart keys.
Smart keys are dangerous in a data warehouse dimension table for several reasons.
The generation of these keys is held hostage to the rules for their syntax. It is tempting to write applications and user interfaces that would make these keys visible to someone. They are just integers and you can't compute with them. This allows any fact table to be physically partitioned on the basis of the surrogate time key. Physically partitioning a large fact table on the basis of time is a very natural approach in any case, because it allows old data to be removed gracefully, and it allows the newest data to be re-indexed and augmented without disturbing the rest of the fact table, if you are using the table partitioning features of your database.