Python text appender
If you don't want to write to the file directly and want to "apply" the changes at once, instead of writing to a temp file, you can keep the changes in memory - in a list of strings:

from sys import argv
from datetime import datetime
import os


if __name__ == '__main__':
    _, typed = argv
    filename = typed + ".txt"
    save_location = os.path.join('/home/user/', filename)

    print(save_location)
    print("Aditor: a digital typewriter, Type: d when done")

    date = datetime.now().strftime("%Y/%m/%d")

    cache = ["\n", date]
    while True:
        entry = input()
        cache.append("\n")

        if entry == 'done' or entry == 'd':
            break

        cache.append(entry)

    with open(save_location, "a") as f:
        f.writelines(cache)


Note that I've removed everything related to handling the temp file.



Also there were some other changes applied in the code above:


using 4 spaces for indentation
used _ for a "throwaway" variable (the script name is not used)
fixed the variable naming - words need to be separated with an underscore - save_location instead of savelocation (PEP8 reference)
checking for "done" using simple comparisons with done and d
using strftime() to dump a datetime into string
putting the code to under if __name__ == '__main__': to avoid the code to be executed if imported
organized imports per PEP8 (reference)