Yes, if they were Weeklys.
Looking at SPX, let’s consider buying one 1975 Put (Oct 24 expiration) and Selling 1 1975 put (Oct 10 expiration).
The long is around 24 days from expiration and the short is about 10 days from expiration. The cost or debit with SPX around 1975 is around $865 for 1 contract.
The trade is relatively neutral with SPX around $1975. The positive theta is $37 daily and the Vega is 71.
The Calendar is positive theta because our short option is decaying quicker than the long option because it expires quicker.
Theta to Vega
The ratio of theta to Vega is approximately 2:1, this means if Implied Volatility decreases 1 point, the trade will lose approximately $75 from Vega. 2 Days of theta will make up for this.
Contrasting this with a farther out Calendar consisting of selling November and buying December, things are much different.
If I buy 1 December 1975 Put and sell 1 November 1975 Put, the debit is around $1200. The theta is 6 and the Vega is 71. The Theta /Vega ratio is around 12:1.
This means if Implied Volatility decreases 1 Point, the Vega tells us we will lose around $71. It would take about 12 quiet days for theta to make this back.
Conclusion: As Implied Volatility levels increase, I get concerned that they might drop. We currently were over 16 in VIX from the 10-11 level, not too long ago. If the market goes up and Volatility decreases over the next few days, being closer in with my duration on Calendars will make life much easier to bear!