At times the Torah describes that something should be done תמיד (regularly). In the instances this term is used, two possibilities arise as to what exactly the time frame of תמיד is. On the one hand it could mean constantly or always. In such a case the act the Torah designates as being תמיד must be done every second of every day. One example of this is the לחם הפנים which the Torah says should be לפני ד' תמיד "before Hashem always". (ויקרא כד:ח). Indeed throughout the duration of the week the לחם הפנים remained on theשלחן at all times. However there is another meaning to the word תמיד, which doesn't mean always but rather continuously. It says that something must be done on a continuous basis. In such a case, the act prescribed by the Torah, can be done even on a daily basis. For instance the קרבן תמיד was brought twice a day, (במדבר כח:ז) and not every second. Yet it is still referred to as שנים ליום עולה תמיד. With this in mind, the pasuk at the beginning of Parshat Tetzave carries with it two possible interpretations. The Torah tells us that the pure olive oil would be use to להעלות נר תמיד, so that the fire could burn תמיד (שמות כז:כ). The תמיד used here to describe the menorah could mean that the fire would have to burn all day. On the other hand, it could mean that once a day you would have to light the מנורה but not necessarily every second. It is comparable to תמיד, by the לחם הפנים, or a קרבן תמיד?
Rashi, כז:כ ד"ה תמיד() writes that the תמיד used here by the מנורה is comparable to the עלות תמיד. He explains that the fact that the מנורה was lit every night is considered to be תמיד. The Ibn Ezra, likewise, interprets the pasuk to mean every night. The Rambam, though, compares the תמיד by the מנורה to that of the לחם הפנים. He says that the מנורה was lit every second of the day. All the wicks would be lit at night and in the morning some were left burning throughout the day. He discusses exactly which wick was left burning all day. Nonetheless, according to the Rambam, the תמיד of the מנורה means always, at all times.
Similarly, although we may not be involved in Torah study on a constant basis, it is vital that we study Torah regularly If we set aside time to study Torah as much as we can, it can be considered as if we are learning Torah constantly.