Hello @rahulprakash , welcome to the forum.
How often do you practice your flute now? Do you own a flute?
Would you like to practice for at least 30min each day every day?
Would you instead like to practice for an average of 30min per day?
How could you be entering data into Beeminder? Website? Mobile App? Integration?
What counts to you as practicing flute? Standing next to a chair with your flute in your hand? Blowing into it for a full thirty minutes? Practicing a song or two or some notes again and again for the 30min?
This is something you want, right? You would like to be better at playing the instrument or would like to play a particular song by a particular date?
For my ‘practice instrument’ goals, I have been setting up two: one for the number of sessions and one for the amount of time. Sometimes it goes well and I can practice say for an hour or 90 minutes but that should not then mean that I do not touch the instrument again for an extra week.
(A particular tool I use also provides stats on number of notes and chords and I record that too in yet another goal. Thus it is not enough that I just jam and freestyle, counting the session and time spent, as I also have a particular curriculum and wish to practice in a more structured manner.)
For others with time components, I have told myself (and noted in the fine print) that I will only count the minutes having used a timer. There are a few activities I wish to do more of but not just the casual happen to be passing by and I can do that now for a few minutes. Instead I want to be aware enough of what I am about to do that I set up the timer for it. (Plus I can be more sure of the time and need not second guess myself if I am just ‘remembering’ that I did that thing for as long as I am about to say I did.)
You can start a do-more goal with a relatively mild slope of say 30min per week. Here you would be tracking “minutes”. You enter two datapoints, the first is when you started your session where you enter the value 0 but note the start time in the comment. Then you practice. Then you do the same but entering the number of minutes practiced as the value and the end time in the comments.
Similarly, you could do the same but track “practice sessions” where you just enter 1 as the value indicating you did it.
I think you can do this and I think you can learn for yourself how you can report it accurately. Be honest with yourself. Start with a doable slope to get a feeling for how it goes, how you may wish to enter data. The trick is to build up a habit and some confidence (and perhaps pride) before arriving at the otherwise daunting-looking challenge of being at the end of the week but having not practiced at all and now needing to enter some big number or fall off.
It has also helped me to describe the thing being practiced in the comment - chords, notes, songs. The more elaborate the lie would need to become, perhaps the less likely I would have been fabricating it.
Good luck and let us know what you tried out, how it went, and with what you ended up!