It is not in practice to change wick every day. The same wick used in the morning can be used again in the evening.
Notes:
Normally the lamp is cleaned during Mondays and Thursdays for using it afresh during Tuesdays and Fridays.
When we use the cleaned lamp, we light it with new wick.
Some house follows the rule of not touching the used wick. Elders say women are exempted from this rule. While some others say one should take bath if they touch used wick, though women are excluded. One can use something to thread the wick end instead of touching it with bare hands and no need to use new wick.
While these are general practice, one can seek the advice of the household elders and follow them accordingly.