Take a nutrient, such as calcium. According to Wikipedia, the RDA (Recommended Dietary Allowance) for an average healthy 44-year-old male is a daily intake of 1000mg of calcium.
Suppose you consumed, over a week, 7000mg of calcium. On average, you consumed 1000mg of calcium per day, which is exactly the recommendation. That's only the average, though, so you might have consumed 500mg of calcium on Monday (50% of the RDA), and 1500mg on Tuesday (150% of the RDA); and so on, with similar variance.
Are you still satisfying your calcium needs? Is there a rule of thumb for determining that for other nutrients, or any pointers to resources that covers the specific cases? Thanks!