Often the use of the simple present tense suffices to indicate that an assertion is being made about the present state of affairs, including the “factual present” sense used when making generalizations or statements about habitual behaviour: Such formalities are dispensed with. But when making a contrast to the past, or emphasizing that the present situation is subject to change, a temporal adverb such as “at present” or “today” is needed: Nowadays such formalities are dispensed with. More people use public transport today. Currently there are no concerns about security.
Likewise, the present continuous can usually stand by itself to signal an ongoing present. But if the reader is being asked to focus in on the present window, drawing attention to the mutable nature of present events, an adverb can be used: The company’s share prices are soaring [statement of present state of affairs] vs. Currently the company’s share prices are soaring [but we expect them to stop doing so].
All the temporal markers featured below may appear at the beginning, middle or end of a sentence, with slight changes of emphasis accordingly: if placed finally in a clause (the stress position) there is a corresponding emphasis on, for example, the temporariness of the statement being made; if placed at the start, the transition to a temporal present is being made; if placed in the middle, after a main subject or verb, the temporal present is tied more closely to this subject/verb, and is likely to be more incidental to the main import of the sentence as a whole. I will begin now [an alert to commencing presently]. Now I will begin [having waited, it is time to begin]. I will now begin [I am going to start].
At present and at the moment have related adverbial functions of signalling that the observation being made is at the current point in time or short period. The first relates an ongoing present, the second a current observation at the present point in time (which allows for a greater possibility of a new observation changing things). There are at present no signs of reconciliation between the two parties [current appearances indicate this to be the case]. There are no signs of reconciliation at the moment [but perhaps this may change soon]. At the present time and at this present time perform a similar function, with more weight being placed on the conditioning of the statement being made being subject to change in future. At the present time there are no signs of reconciliation.
In the present is more used in set phrases such as live in the present. Presently does not mean ‘at present’ but rather ‘in a moment’, used with a future tense: Presently we shall see how this argument falls down.
Now is used to signal a change from a past condition to a present one: Now hopes are foundering in any reconciliation between the two parties. Nowadays, or the less formal these days, is used to mark a statement of how things are presently, in a general, widespread or habitual sense rather than of momentary phenomena, again with an implication of contrast with the past: Nowadays people are quicker to lose hope. Summers are hotter these days. The idiom in this day and age is informal; in formal prose, if any additional temporal marker is needed, ‘nowadays’ serves.
Today may refer to the current calendar day when referring to an event (The stock market fell sharply today) or as an adverb similar to ‘nowadays’ when making generalizations comparing with the past: Today people prefer to work fewer hours per week. The stock market is closely regulated today. (Returning to the effect of repositioning adverbs, the alternative The stock market today is closely regulated puts less emphasis on the change from past to present practice, just asserting that this is present practice; the further alternative Today the stock market today is closely regulated effects a temporal shift from the time of the preceding text to the present day, and emphasizes the present practice of tight regulation – probably the latter will be picked up as the topic of the next sentence.)
To this day means ‘up until the present’: A tradition was thereby established which continues to this day. An alternative is (up) to the present day: Such practices continue to the present day.
Currently is used to signal that the statement being made of the present is subject to change: Currently the government does not see a reason to intervene. Recently, or the allied phrases in recent days, in recent years or in recent decades that specify the period in question more precisely, is used to signal a change from past to present; the difference from ‘now’ (which also signals such a change) is that ‘recently’ specifies the change from past to present to be gradual, over a period of time, with an according use of the present perfect continuous: Recently hopes have been foundering in any reconciliation between the two parties.
Nowadays, these days or today? (Cambridge)
Today, present day, and nowadays (Brittanica)
