The beauty of spiritual practice is that it can always be done right now. You may wait until next week to begin your new diet. You may wait to get over your cold before beginning your new exercise routine. However, spirituality can always be done immediately.
You may have a goal to eliminate anger. You may remember this goal in the midst of a heated debate. Don’t say “oh well, next week I’ll be calm”. Instead, start dealing with that anger right away. This is one of the most important times to practice. Likewise, when you feel miserably sick and in pain, that is one of the best times to practice being at peace, maintaining a joyful mind and so forth.
It is often tempting to postpone a goal until you are feeling better or have more time. This is not true of spiritual practices. The best time for them is always now, and even a very little of it does great good.