After 1. sarva 'all' 2. eka 'one' 3. anya 'other' 4. kim 'what' 5 yad 'which' and 6. tad 'that' when time is denoted comes the affix dā , the words being in the Locative -7th case.,
The word सप्तम्याः 5.2.10 is understood here and not the word इतराभ्यां of the last. This debars त्रल् ॥ Thus सर्वदा or सदा 5.3.6 'at every time' or 'always', एकदा 'once', अन्यदा 'at another time' कदा 7.2.103 'when', यदा 'when', तदा 'then'.
Why do we say काले 'when time is denoted'? Observe सर्वत्रदेशे (where although the case is the 7th, the affix is not दा, because the sense is) 'in every place' or 'every where'.,